diff --git a/web/account/siwe-login-form.react.js b/web/account/siwe-login-form.react.js
index 4c2c97e69..82c2e0f51 100644
--- a/web/account/siwe-login-form.react.js
+++ b/web/account/siwe-login-form.react.js
@@ -1,319 +1,328 @@
 // @flow
 
 import '@rainbow-me/rainbowkit/styles.css';
 import classNames from 'classnames';
 import invariant from 'invariant';
 import * as React from 'react';
 import { useAccount, useWalletClient } from 'wagmi';
 
 import { setDataLoadedActionType } from 'lib/actions/client-db-store-actions.js';
 import {
   getSIWENonce,
   getSIWENonceActionTypes,
   legacySiweAuth,
   legacySiweAuthActionTypes,
 } from 'lib/actions/siwe-actions.js';
 import {
   identityGenerateNonceActionTypes,
   useIdentityGenerateNonce,
 } from 'lib/actions/user-actions.js';
 import ConnectedWalletInfo from 'lib/components/connected-wallet-info.react.js';
 import SWMansionIcon from 'lib/components/swmansion-icon.react.js';
 import stores from 'lib/facts/stores.js';
 import { useWalletLogIn } from 'lib/hooks/login-hooks.js';
 import { useLegacyAshoatKeyserverCall } from 'lib/keyserver-conn/legacy-keyserver-call.js';
 import { legacyLogInExtraInfoSelector } from 'lib/selectors/account-selectors.js';
 import { createLoadingStatusSelector } from 'lib/selectors/loading-selectors.js';
 import type {
   LegacyLogInStartingPayload,
   LegacyLogInExtraInfo,
 } from 'lib/types/account-types.js';
 import { SIWEMessageTypes } from 'lib/types/siwe-types.js';
-import { getMessageForException, ServerError } from 'lib/utils/errors.js';
+import { getMessageForException } from 'lib/utils/errors.js';
 import { useDispatchActionPromise } from 'lib/utils/redux-promise-utils.js';
 import { useDispatch } from 'lib/utils/redux-utils.js';
 import { usingCommServicesAccessToken } from 'lib/utils/services-utils.js';
 import {
   createSIWEMessage,
   getSIWEStatementForPublicKey,
   siweMessageSigningExplanationStatements,
 } from 'lib/utils/siwe-utils.js';
 
 import HeaderSeparator from './header-separator.react.js';
 import css from './siwe.css';
 import Button from '../components/button.react.js';
 import OrBreak from '../components/or-break.react.js';
 import { olmAPI } from '../crypto/olm-api.js';
 import LoadingIndicator from '../loading-indicator.react.js';
 import { useSelector } from '../redux/redux-utils.js';
+import { getVersionUnsupportedError } from '../utils/version-utils.js';
 
-type SIWELogInError = 'account_does_not_exist';
+type SIWELogInError = 'account_does_not_exist' | 'client_version_unsupported';
 
 type SIWELoginFormProps = {
   +cancelSIWEAuthFlow: () => void,
 };
 
 const legacyGetSIWENonceLoadingStatusSelector = createLoadingStatusSelector(
   getSIWENonceActionTypes,
 );
 const identityGenerateNonceLoadingStatusSelector = createLoadingStatusSelector(
   identityGenerateNonceActionTypes,
 );
 const legacySiweAuthLoadingStatusSelector = createLoadingStatusSelector(
   legacySiweAuthActionTypes,
 );
 function SIWELoginForm(props: SIWELoginFormProps): React.Node {
   const { address } = useAccount();
   const { data: signer } = useWalletClient();
   const dispatchActionPromise = useDispatchActionPromise();
   const legacyGetSIWENonceCall = useLegacyAshoatKeyserverCall(getSIWENonce);
   const legacyGetSIWENonceCallLoadingStatus = useSelector(
     legacyGetSIWENonceLoadingStatusSelector,
   );
   const identityGenerateNonce = useIdentityGenerateNonce();
   const identityGenerateNonceLoadingStatus = useSelector(
     identityGenerateNonceLoadingStatusSelector,
   );
   const siweAuthLoadingStatus = useSelector(
     legacySiweAuthLoadingStatusSelector,
   );
   const legacySiweAuthCall = useLegacyAshoatKeyserverCall(legacySiweAuth);
   const legacyLogInExtraInfo = useSelector(legacyLogInExtraInfoSelector);
 
   const walletLogIn = useWalletLogIn();
 
   const [siweNonce, setSIWENonce] = React.useState<?string>(null);
 
   const siweNonceShouldBeFetched =
     !siweNonce &&
     legacyGetSIWENonceCallLoadingStatus !== 'loading' &&
     identityGenerateNonceLoadingStatus !== 'loading';
 
   React.useEffect(() => {
     if (!siweNonceShouldBeFetched) {
       return;
     }
     if (usingCommServicesAccessToken) {
       void dispatchActionPromise(
         identityGenerateNonceActionTypes,
         (async () => {
           const response = await identityGenerateNonce();
           setSIWENonce(response);
         })(),
       );
     } else {
       void dispatchActionPromise(
         getSIWENonceActionTypes,
         (async () => {
           const response = await legacyGetSIWENonceCall();
           setSIWENonce(response);
         })(),
       );
     }
   }, [
     dispatchActionPromise,
     identityGenerateNonce,
     legacyGetSIWENonceCall,
     siweNonceShouldBeFetched,
   ]);
 
   const callLegacySIWEAuthEndpoint = React.useCallback(
     async (
       message: string,
       signature: string,
       extraInfo: LegacyLogInExtraInfo,
     ) => {
       await olmAPI.initializeCryptoAccount();
       const userPublicKey = await olmAPI.getUserPublicKey();
       try {
         return await legacySiweAuthCall({
           message,
           signature,
           signedIdentityKeysBlob: {
             payload: userPublicKey.blobPayload,
             signature: userPublicKey.signature,
           },
           doNotRegister: true,
           ...extraInfo,
         });
       } catch (e) {
-        if (
-          e instanceof ServerError &&
-          e.message === 'account_does_not_exist'
-        ) {
+        const messageForException = getMessageForException(e);
+        if (messageForException === 'account_does_not_exist') {
           setError('account_does_not_exist');
+        } else if (messageForException === 'client_version_unsupported') {
+          setError('client_version_unsupported');
         }
         throw e;
       }
     },
     [legacySiweAuthCall],
   );
 
   const attemptLegacySIWEAuth = React.useCallback(
     (message: string, signature: string) => {
       return dispatchActionPromise(
         legacySiweAuthActionTypes,
         callLegacySIWEAuthEndpoint(message, signature, legacyLogInExtraInfo),
         undefined,
         ({
           calendarQuery: legacyLogInExtraInfo.calendarQuery,
         }: LegacyLogInStartingPayload),
       );
     },
     [callLegacySIWEAuthEndpoint, dispatchActionPromise, legacyLogInExtraInfo],
   );
 
   const attemptWalletLogIn = React.useCallback(
     async (
       walletAddress: string,
       siweMessage: string,
       siweSignature: string,
     ) => {
       try {
         return await walletLogIn(walletAddress, siweMessage, siweSignature);
       } catch (e) {
-        if (getMessageForException(e) === 'user not found') {
+        const messageForException = getMessageForException(e);
+        if (messageForException === 'user not found') {
           setError('account_does_not_exist');
+        } else if (
+          messageForException === 'client_version_unsupported' ||
+          messageForException === 'Unsupported version'
+        ) {
+          setError('client_version_unsupported');
         }
         throw e;
       }
     },
     [walletLogIn],
   );
 
   const dispatch = useDispatch();
   const onSignInButtonClick = React.useCallback(async () => {
     invariant(signer, 'signer must be present during SIWE attempt');
     invariant(siweNonce, 'nonce must be present during SIWE attempt');
     await olmAPI.initializeCryptoAccount();
     const {
       primaryIdentityPublicKeys: { ed25519 },
     } = await olmAPI.getUserPublicKey();
     const statement = getSIWEStatementForPublicKey(
       ed25519,
       SIWEMessageTypes.MSG_AUTH,
     );
     const message = createSIWEMessage(address, statement, siweNonce);
     const signature = await signer.signMessage({ message });
     if (usingCommServicesAccessToken) {
       await attemptWalletLogIn(address, message, signature);
     } else {
       await attemptLegacySIWEAuth(message, signature);
       dispatch({
         type: setDataLoadedActionType,
         payload: {
           dataLoaded: true,
         },
       });
     }
   }, [
     address,
     attemptLegacySIWEAuth,
     attemptWalletLogIn,
     signer,
     siweNonce,
     dispatch,
   ]);
 
   const { cancelSIWEAuthFlow } = props;
 
   const backButtonColor = React.useMemo(
     () => ({ backgroundColor: '#211E2D' }),
     [],
   );
 
   const signInButtonColor = React.useMemo(
     () => ({ backgroundColor: '#6A20E3' }),
     [],
   );
 
   const [error, setError] = React.useState<?SIWELogInError>();
 
   const mainMiddleAreaClassName = classNames({
     [css.mainMiddleArea]: true,
     [css.hidden]: !!error,
   });
   const errorOverlayClassNames = classNames({
     [css.errorOverlay]: true,
     [css.hidden]: !error,
   });
 
   if (siweAuthLoadingStatus === 'loading' || !siweNonce) {
     return (
       <div className={css.loadingIndicator}>
         <LoadingIndicator status="loading" size="large" />
       </div>
     );
   }
 
   let errorText;
   if (error === 'account_does_not_exist') {
     errorText = (
       <>
         <p className={css.redText}>
           No Comm account found for that Ethereum wallet!
         </p>
         <p>
           We require that users register on their mobile devices. Comm relies on
           a primary device capable of scanning QR codes in order to authorize
           secondary devices.
         </p>
         <p>
           You can install our iOS app&nbsp;
           <a href={stores.appStoreUrl} target="_blank" rel="noreferrer">
             here
           </a>
           , or our Android app&nbsp;
           <a href={stores.googlePlayUrl} target="_blank" rel="noreferrer">
             here
           </a>
           .
         </p>
       </>
     );
+  } else if (error === 'client_version_unsupported') {
+    errorText = <p className={css.redText}>{getVersionUnsupportedError()}</p>;
   }
 
   return (
     <div className={css.siweLoginFormContainer}>
       <h4>Sign in with Ethereum</h4>
       <HeaderSeparator />
       <div className={css.walletConnectedText}>
         <p>Wallet Connected</p>
       </div>
       <div className={css.connectButtonContainer}>
         <ConnectedWalletInfo />
       </div>
       <div className={css.middleArea}>
         <div className={mainMiddleAreaClassName}>
           <div className={css.messageSigningStatements}>
             <p>{siweMessageSigningExplanationStatements}</p>
             <p>
               By signing up, you agree to our{' '}
               <a href="https://comm.app/terms">Terms of Use</a> &{' '}
               <a href="https://comm.app/privacy">Privacy Policy</a>.
             </p>
           </div>
           <Button
             variant="filled"
             onClick={onSignInButtonClick}
             buttonColor={signInButtonColor}
           >
             Sign in using this wallet
           </Button>
         </div>
         <div className={errorOverlayClassNames}>{errorText}</div>
       </div>
       <OrBreak />
       <Button
         variant="filled"
         onClick={cancelSIWEAuthFlow}
         buttonColor={backButtonColor}
       >
         <SWMansionIcon icon="chevron-left" size={18} />
         Back to sign in with username
       </Button>
     </div>
   );
 }
 
 export default SIWELoginForm;
diff --git a/web/account/traditional-login-form.react.js b/web/account/traditional-login-form.react.js
index 78ace2595..6484e4fa3 100644
--- a/web/account/traditional-login-form.react.js
+++ b/web/account/traditional-login-form.react.js
@@ -1,258 +1,267 @@
 // @flow
 
 import invariant from 'invariant';
 import * as React from 'react';
 
 import {
   useLegacyLogIn,
   legacyLogInActionTypes,
 } from 'lib/actions/user-actions.js';
 import { useModalContext } from 'lib/components/modal-provider.react.js';
 import { usePasswordLogIn } from 'lib/hooks/login-hooks.js';
 import { legacyLogInExtraInfoSelector } from 'lib/selectors/account-selectors.js';
 import { createLoadingStatusSelector } from 'lib/selectors/loading-selectors.js';
 import {
   oldValidUsernameRegex,
   validEmailRegex,
 } from 'lib/shared/account-utils.js';
 import type {
   LegacyLogInExtraInfo,
   LegacyLogInStartingPayload,
 } from 'lib/types/account-types.js';
 import { logInActionSources } from 'lib/types/account-types.js';
 import { getMessageForException } from 'lib/utils/errors.js';
 import { useDispatchActionPromise } from 'lib/utils/redux-promise-utils.js';
 import { usingCommServicesAccessToken } from 'lib/utils/services-utils.js';
 
 import HeaderSeparator from './header-separator.react.js';
 import css from './log-in-form.css';
 import PasswordInput from './password-input.react.js';
 import Button from '../components/button.react.js';
 import { olmAPI } from '../crypto/olm-api.js';
 import LoadingIndicator from '../loading-indicator.react.js';
 import Input from '../modals/input.react.js';
 import { useSelector } from '../redux/redux-utils.js';
+import { getShortVersionUnsupportedError } from '../utils/version-utils.js';
 
 const loadingStatusSelector = createLoadingStatusSelector(
   legacyLogInActionTypes,
 );
 function TraditionalLoginForm(): React.Node {
   const legacyAuthInProgress = useSelector(loadingStatusSelector) === 'loading';
   const [identityAuthInProgress, setIdentityAuthInProgress] =
     React.useState(false);
   const inputDisabled = legacyAuthInProgress || identityAuthInProgress;
 
   const legacyLoginExtraInfo = useSelector(legacyLogInExtraInfoSelector);
   const callLegacyLogIn = useLegacyLogIn();
 
   const dispatchActionPromise = useDispatchActionPromise();
   const modalContext = useModalContext();
 
   const usernameInputRef = React.useRef<?HTMLInputElement>();
   React.useEffect(() => {
     usernameInputRef.current?.focus();
   }, []);
 
   const [username, setUsername] = React.useState<string>('');
   const onUsernameChange = React.useCallback(
     (e: SyntheticEvent<HTMLInputElement>) => {
       invariant(e.target instanceof HTMLInputElement, 'target not input');
       setUsername(e.target.value);
     },
     [],
   );
 
   const onUsernameBlur = React.useCallback(() => {
     setUsername(untrimmedUsername => untrimmedUsername.trim());
   }, []);
 
   const [password, setPassword] = React.useState<string>('');
   const onPasswordChange = React.useCallback(
     (e: SyntheticEvent<HTMLInputElement>) => {
       invariant(e.target instanceof HTMLInputElement, 'target not input');
       setPassword(e.target.value);
     },
     [],
   );
 
   const [errorMessage, setErrorMessage] = React.useState<string>('');
 
   const legacyLogInAction = React.useCallback(
     async (extraInfo: LegacyLogInExtraInfo) => {
       await olmAPI.initializeCryptoAccount();
       const userPublicKey = await olmAPI.getUserPublicKey();
       try {
         const result = await callLegacyLogIn({
           ...extraInfo,
           username,
           password,
           authActionSource: logInActionSources.logInFromWebForm,
           signedIdentityKeysBlob: {
             payload: userPublicKey.blobPayload,
             signature: userPublicKey.signature,
           },
         });
         modalContext.popModal();
         return result;
       } catch (e) {
         setUsername('');
         setPassword('');
-        if (getMessageForException(e) === 'invalid_credentials') {
+        const messageForException = getMessageForException(e);
+        if (messageForException === 'invalid_credentials') {
           setErrorMessage('incorrect username or password');
+        } else if (messageForException === 'client_version_unsupported') {
+          setErrorMessage(getShortVersionUnsupportedError());
         } else {
           setErrorMessage('unknown error');
         }
         usernameInputRef.current?.focus();
         throw e;
       }
     },
     [callLegacyLogIn, modalContext, password, username],
   );
 
   const callIdentityPasswordLogIn = usePasswordLogIn();
 
   const identityPasswordLogInAction = React.useCallback(async () => {
     if (identityAuthInProgress) {
       return;
     }
     setIdentityAuthInProgress(true);
     try {
       await callIdentityPasswordLogIn(username, password);
       modalContext.popModal();
     } catch (e) {
       setUsername('');
       setPassword('');
       const messageForException = getMessageForException(e);
       if (
         messageForException === 'user not found' ||
         messageForException === 'login failed'
       ) {
         setErrorMessage('incorrect username or password');
+      } else if (
+        messageForException === 'client_version_unsupported' ||
+        messageForException === 'Unsupported version'
+      ) {
+        setErrorMessage(getShortVersionUnsupportedError());
       } else {
         setErrorMessage('unknown error');
       }
       usernameInputRef.current?.focus();
       throw e;
     } finally {
       setIdentityAuthInProgress(false);
     }
   }, [
     identityAuthInProgress,
     callIdentityPasswordLogIn,
     modalContext,
     password,
     username,
   ]);
 
   const onSubmit = React.useCallback(
     (event: SyntheticEvent<HTMLElement>) => {
       event.preventDefault();
 
       if (username.search(validEmailRegex) > -1) {
         setUsername('');
         setErrorMessage('usernames only, not emails');
         usernameInputRef.current?.focus();
         return;
       } else if (username.search(oldValidUsernameRegex) === -1) {
         setUsername('');
         setErrorMessage('alphanumeric usernames only');
         usernameInputRef.current?.focus();
         return;
       } else if (password === '') {
         setErrorMessage('password is empty');
         usernameInputRef.current?.focus();
         return;
       }
       if (usingCommServicesAccessToken) {
         void identityPasswordLogInAction();
       } else {
         void dispatchActionPromise(
           legacyLogInActionTypes,
           legacyLogInAction(legacyLoginExtraInfo),
           undefined,
           ({
             calendarQuery: legacyLoginExtraInfo.calendarQuery,
           }: LegacyLogInStartingPayload),
         );
       }
     },
     [
       dispatchActionPromise,
       identityPasswordLogInAction,
       legacyLogInAction,
       legacyLoginExtraInfo,
       username,
       password,
     ],
   );
 
   const loadingIndicatorClassName = inputDisabled
     ? css.loadingIndicator
     : css.hiddenLoadingIndicator;
   const buttonTextClassName = inputDisabled
     ? css.invisibleButtonText
     : undefined;
   const loginButtonContent = React.useMemo(
     () => (
       <>
         <div className={loadingIndicatorClassName}>
           <LoadingIndicator status="loading" />
         </div>
         <div className={buttonTextClassName}>Sign in</div>
       </>
     ),
     [loadingIndicatorClassName, buttonTextClassName],
   );
 
   const signInButtonColor = React.useMemo(
     () => ({ backgroundColor: '#6A20E3' }),
     [],
   );
 
   return (
     <form method="POST">
       <div>
         <h4>Sign in to Comm</h4>
         <HeaderSeparator />
         <div className={css.form_title}>Username</div>
         <div className={css.form_content}>
           <Input
             className={css.input}
             type="text"
             placeholder="Username"
             value={username}
             onChange={onUsernameChange}
             onBlur={onUsernameBlur}
             ref={usernameInputRef}
             disabled={inputDisabled}
           />
         </div>
       </div>
       <div>
         <div className={css.form_title}>Password</div>
         <div className={css.form_content}>
           <PasswordInput
             className={css.input}
             value={password}
             onChange={onPasswordChange}
             disabled={inputDisabled}
           />
         </div>
       </div>
       <div className={css.form_footer}>
         <Button
           variant="filled"
           type="submit"
           disabled={inputDisabled}
           onClick={onSubmit}
           buttonColor={signInButtonColor}
         >
           {loginButtonContent}
         </Button>
         <div className={css.modal_form_error}>{errorMessage}</div>
       </div>
     </form>
   );
 }
 
 export default TraditionalLoginForm;
diff --git a/web/utils/version-utils.js b/web/utils/version-utils.js
index ff53a3a17..59e13c934 100644
--- a/web/utils/version-utils.js
+++ b/web/utils/version-utils.js
@@ -1,18 +1,27 @@
 // @flow
 
 import { isDesktopPlatform } from 'lib/types/device-types.js';
 import { getConfig } from 'lib/utils/config.js';
 
 function getVersionUnsupportedError(): string {
   const actionRequestMessage = isDesktopPlatform(
     getConfig().platformDetails.platform,
   )
     ? 'Please reload the app'
     : 'Please refresh the page';
   return (
     'Your app version is pretty old, and the server doesn’t know how ' +
     `to speak to it anymore. ${actionRequestMessage}.`
   );
 }
 
-export { getVersionUnsupportedError };
+function getShortVersionUnsupportedError(): string {
+  const actionRequestMessage = isDesktopPlatform(
+    getConfig().platformDetails.platform,
+  )
+    ? 'please reload'
+    : 'please refresh';
+  return `client version unsupported. ${actionRequestMessage}`;
+}
+
+export { getVersionUnsupportedError, getShortVersionUnsupportedError };