diff --git a/web/app.react.js b/web/app.react.js
--- a/web/app.react.js
+++ b/web/app.react.js
@@ -47,6 +47,7 @@
 import { EditModalProvider } from './chat/edit-message-provider.js';
 import { MemberListSidebarProvider } from './chat/member-list-sidebar/member-list-sidebar-provider.react.js';
 import NavigationArrows from './components/navigation-arrows.react.js';
+import MinVersionHandler from './components/version-handler.react.js';
 import { olmAPI } from './crypto/olm-api.js';
 import electron from './electron.js';
 import InputStateContainer from './input/input-state-container.react.js';
@@ -226,6 +227,7 @@
                     <PushNotificationsHandler />
                     <InviteLinkHandler />
                     <InviteLinksRefresher />
+                    <MinVersionHandler />
                     {content}
                   </ChatMentionContextProvider>
                 </MessageSearchStateProvider>
diff --git a/web/components/version-handler.css b/web/components/version-handler.css
new file mode 100644
--- /dev/null
+++ b/web/components/version-handler.css
@@ -0,0 +1,21 @@
+.modalContent {
+  color: var(--text-background-primary-default);
+  font-size: var(--s-font-14);
+  margin-top: 8px;
+  display: flex;
+}
+
+.wrapper {
+  display: flex;
+  flex-shrink: 1;
+  justify-content: center;
+}
+
+.ancestryContainer {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  height: 40px;
+  background-color: var(--frame-background-tertiary-default);
+  margin-top: 20px;
+}
diff --git a/web/components/version-handler.react.js b/web/components/version-handler.react.js
new file mode 100644
--- /dev/null
+++ b/web/components/version-handler.react.js
@@ -0,0 +1,86 @@
+// @flow
+
+import * as React from 'react';
+
+import { useModalContext } from 'lib/components/modal-provider.react.js';
+import ashoat from 'lib/facts/ashoat.js';
+
+import KeyserverPill from './keyserver-pill.react.js';
+import css from './version-handler.css';
+import Modal from '../modals/modal.react.js';
+import { useSelector } from '../redux/redux-utils.js';
+
+type ModalProps = {
+  +keyserverName: string,
+};
+
+function VersionUnsupportedModal(props: ModalProps): React.Node {
+  const { popModal } = useModalContext();
+
+  const subheader = React.useMemo(
+    () => (
+      <div className={css.ancestryContainer}>
+        <KeyserverPill keyserverAdminUsername={props.keyserverName} />
+      </div>
+    ),
+    [props.keyserverName],
+  );
+
+  return (
+    <Modal
+      name="App version unsupported"
+      onClose={popModal}
+      size="large"
+      subheader={subheader}
+    >
+      <div className={css.modalContent}>
+        Your app version is pretty old, and the server doesn’t know how to speak
+        to it anymore. Please reload the app.
+      </div>
+    </Modal>
+  );
+}
+
+type Props = {
+  +keyserverID: string,
+};
+
+function SingleKeyserverMinVersionHandler(props: Props): null {
+  const { keyserverID } = props;
+
+  const connectionIssue = useSelector(
+    state =>
+      state.keyserverStore.keyserverInfos[keyserverID].connection
+        .connectionIssue,
+  );
+
+  const admin = useSelector(state => state.userStore[keyserverID]);
+  let keyserverName = admin?.username;
+  if (!keyserverName) {
+    keyserverName = keyserverID === ashoat.id ? ashoat.username : keyserverID;
+  }
+
+  const { pushModal } = useModalContext();
+
+  React.useEffect(() => {
+    if (connectionIssue === 'client_version_unsupported') {
+      pushModal(<VersionUnsupportedModal keyserverName={keyserverName} />);
+    }
+  }, [keyserverName, connectionIssue, keyserverID, pushModal]);
+
+  return null;
+}
+const MemoizedSingleKeyserverMinVersionHandler: React.ComponentType<Props> =
+  React.memo<Props>(SingleKeyserverMinVersionHandler);
+
+function MinVersionHandler(): React.Node {
+  const keyserverIDs = useSelector(state =>
+    Object.keys(state.keyserverStore.keyserverInfos),
+  );
+
+  return keyserverIDs.map(id => (
+    <MemoizedSingleKeyserverMinVersionHandler keyserverID={id} key={id} />
+  ));
+}
+
+export default MinVersionHandler;