diff --git a/keyserver/src/creators/thread-creator.js b/keyserver/src/creators/thread-creator.js
index 22a828e64..e670b29dd 100644
--- a/keyserver/src/creators/thread-creator.js
+++ b/keyserver/src/creators/thread-creator.js
@@ -1,508 +1,509 @@
 // @flow
 
 import invariant from 'invariant';
 
 import bots from 'lib/facts/bots.js';
 import genesis from 'lib/facts/genesis.js';
 import { getRolePermissionBlobs } from 'lib/permissions/thread-permissions.js';
 import {
   generatePendingThreadColor,
   generateRandomColor,
 } from 'lib/shared/color-utils.js';
 import { getThreadTypeParentRequirement } from 'lib/shared/thread-utils.js';
 import type { Shape } from 'lib/types/core.js';
 import { messageTypes } from 'lib/types/message-types-enum.js';
 import { threadPermissions } from 'lib/types/thread-permission-types.js';
 import {
   threadTypes,
   threadTypeIsCommunityRoot,
 } from 'lib/types/thread-types-enum.js';
 import {
   type ServerNewThreadRequest,
   type NewThreadResponse,
 } from 'lib/types/thread-types.js';
 import type { UserInfos } from 'lib/types/user-types.js';
 import { pushAll } from 'lib/utils/array.js';
 import { ServerError } from 'lib/utils/errors.js';
 import { promiseAll } from 'lib/utils/promises.js';
 import { firstLine } from 'lib/utils/string-utils.js';
 
 import createIDs from './id-creator.js';
 import createMessages from './message-creator.js';
 import { createInitialRolesForNewThread } from './role-creator.js';
 import type { UpdatesForCurrentSession } from './update-creator.js';
 import { dbQuery, SQL } from '../database/database.js';
 import {
   fetchLatestEditMessageContentByID,
   fetchMessageInfoByID,
 } from '../fetchers/message-fetchers.js';
 import {
   determineThreadAncestry,
   personalThreadQuery,
 } from '../fetchers/thread-fetchers.js';
 import {
   checkThreadPermission,
   validateCandidateMembers,
 } from '../fetchers/thread-permission-fetchers.js';
 import type { Viewer } from '../session/viewer.js';
 import {
   changeRole,
   recalculateThreadPermissions,
   commitMembershipChangeset,
   getChangesetCommitResultForExistingThread,
 } from '../updaters/thread-permission-updaters.js';
 import { joinThread } from '../updaters/thread-updaters.js';
 import RelationshipChangeset from '../utils/relationship-changeset.js';
 
 const { commbot } = bots;
 
 const privateThreadDescription: string =
   'This is your private chat, ' +
   'where you can set reminders and jot notes in private!';
 
 type CreateThreadOptions = Shape<{
   +forceAddMembers: boolean,
   +updatesForCurrentSession: UpdatesForCurrentSession,
   +silentlyFailMembers: boolean,
 }>;
 
 // If forceAddMembers is set, we will allow the viewer to add random users who
 // they aren't friends with. We will only fail if the viewer is trying to add
 // somebody who they have blocked or has blocked them. On the other hand, if
 // forceAddMembers is not set, we will fail if the viewer tries to add somebody
 // who they aren't friends with and doesn't have a membership row with a
 // nonnegative role for the parent thread.
 async function createThread(
   viewer: Viewer,
   request: ServerNewThreadRequest,
   options?: CreateThreadOptions,
 ): Promise<NewThreadResponse> {
   if (!viewer.loggedIn) {
     throw new ServerError('not_logged_in');
   }
 
   const forceAddMembers = options?.forceAddMembers ?? false;
   const updatesForCurrentSession =
     options?.updatesForCurrentSession ?? 'return';
   const silentlyFailMembers = options?.silentlyFailMembers ?? false;
 
   const threadType = request.type;
   const shouldCreateRelationships =
     forceAddMembers || threadType === threadTypes.PERSONAL;
   let parentThreadID = request.parentThreadID ? request.parentThreadID : null;
   const initialMemberIDsFromRequest =
     request.initialMemberIDs && request.initialMemberIDs.length > 0
       ? [...new Set(request.initialMemberIDs)]
       : null;
   const ghostMemberIDsFromRequest =
     request.ghostMemberIDs && request.ghostMemberIDs.length > 0
       ? [...new Set(request.ghostMemberIDs)]
       : null;
 
   const sourceMessageID = request.sourceMessageID
     ? request.sourceMessageID
     : null;
   invariant(
     threadType !== threadTypes.SIDEBAR || sourceMessageID,
     'sourceMessageID should be set for sidebar',
   );
 
   const parentRequirement = getThreadTypeParentRequirement(threadType);
   if (
     (parentRequirement === 'required' && !parentThreadID) ||
     (parentRequirement === 'disabled' && parentThreadID)
   ) {
     throw new ServerError('invalid_parameters');
   }
 
   if (
     threadType === threadTypes.PERSONAL &&
     request.initialMemberIDs?.length !== 1
   ) {
     throw new ServerError('invalid_parameters');
   }
 
   const requestParentThreadID = parentThreadID;
   const confirmParentPermissionPromise = (async () => {
     if (!requestParentThreadID) {
       return;
     }
     const hasParentPermission = await checkThreadPermission(
       viewer,
       requestParentThreadID,
       threadType === threadTypes.SIDEBAR
         ? threadPermissions.CREATE_SIDEBARS
         : threadPermissions.CREATE_SUBCHANNELS,
     );
     if (!hasParentPermission) {
       throw new ServerError('invalid_credentials');
     }
   })();
 
   // This is a temporary hack until we release actual E2E-encrypted local
   // conversations. For now we are hosting all root threads on Ashoat's
   // keyserver, so we set them to the have the Genesis community as their
   // parent thread.
   if (!parentThreadID && !threadTypeIsCommunityRoot(threadType)) {
     parentThreadID = genesis.id;
   }
 
   const determineThreadAncestryPromise = determineThreadAncestry(
     parentThreadID,
     threadType,
   );
 
   const validateMembersPromise = (async () => {
     const threadAncestry = await determineThreadAncestryPromise;
     const defaultRolePermissions = getRolePermissionBlobs(threadType).Members;
     const { initialMemberIDs, ghostMemberIDs } = await validateCandidateMembers(
       viewer,
       {
         initialMemberIDs: initialMemberIDsFromRequest,
         ghostMemberIDs: ghostMemberIDsFromRequest,
       },
       {
         threadType,
         parentThreadID,
         containingThreadID: threadAncestry.containingThreadID,
         defaultRolePermissions,
       },
       { requireRelationship: !shouldCreateRelationships },
     );
     if (
       !silentlyFailMembers &&
       (Number(initialMemberIDs?.length) <
         Number(initialMemberIDsFromRequest?.length) ||
         Number(ghostMemberIDs?.length) <
           Number(ghostMemberIDsFromRequest?.length))
     ) {
       throw new ServerError('invalid_credentials');
     }
     return { initialMemberIDs, ghostMemberIDs };
   })();
 
   const checkPromises = {};
   checkPromises.confirmParentPermission = confirmParentPermissionPromise;
   checkPromises.threadAncestry = determineThreadAncestryPromise;
   checkPromises.validateMembers = validateMembersPromise;
   if (sourceMessageID) {
     checkPromises.sourceMessage = fetchMessageInfoByID(viewer, sourceMessageID);
   }
   const {
     sourceMessage,
     threadAncestry,
     validateMembers: { initialMemberIDs, ghostMemberIDs },
   } = await promiseAll(checkPromises);
 
   if (
     sourceMessage &&
     (sourceMessage.type === messageTypes.REACTION ||
-      sourceMessage.type === messageTypes.EDIT_MESSAGE)
+      sourceMessage.type === messageTypes.EDIT_MESSAGE ||
+      sourceMessage.type === messageTypes.SIDEBAR_SOURCE)
   ) {
     throw new ServerError('invalid_parameters');
   }
 
   let { id } = request;
   if (id === null || id === undefined) {
     const ids = await createIDs('threads', 1);
     id = ids[0];
   }
   const newRoles = await createInitialRolesForNewThread(id, threadType);
 
   const name = request.name ? firstLine(request.name) : null;
   const description = request.description ? request.description : null;
   let color = request.color
     ? request.color.toLowerCase()
     : generateRandomColor();
   if (threadType === threadTypes.PERSONAL) {
     color = generatePendingThreadColor([
       ...(request.initialMemberIDs ?? []),
       viewer.id,
     ]);
   }
 
   const time = Date.now();
 
   const row = [
     id,
     threadType,
     name,
     description,
     viewer.userID,
     time,
     color,
     parentThreadID,
     threadAncestry.containingThreadID,
     threadAncestry.community,
     threadAncestry.depth,
     newRoles.default.id,
     sourceMessageID,
   ];
 
   let existingThreadQuery = null;
   if (threadType === threadTypes.PERSONAL) {
     const otherMemberID = initialMemberIDs?.[0];
     invariant(
       otherMemberID,
       'Other member id should be set for a PERSONAL thread',
     );
     existingThreadQuery = personalThreadQuery(viewer.userID, otherMemberID);
   } else if (sourceMessageID) {
     existingThreadQuery = SQL`
       SELECT t.id
       FROM threads t
       WHERE t.source_message = ${sourceMessageID}
     `;
   }
 
   if (existingThreadQuery) {
     const query = SQL`
       INSERT INTO threads(id, type, name, description, creator, creation_time,
         color, parent_thread_id, containing_thread_id, community, depth,
         default_role, source_message)
       SELECT ${row}
       WHERE NOT EXISTS (`;
     query.append(existingThreadQuery).append(SQL`)`);
     const [result] = await dbQuery(query);
 
     if (result.affectedRows === 0) {
       const deleteRoles = SQL`
         DELETE FROM roles
         WHERE id IN (${newRoles.default.id}, ${newRoles.creator.id})
       `;
       const deleteIDs = SQL`
         DELETE FROM ids
         WHERE id IN (${id}, ${newRoles.default.id}, ${newRoles.creator.id})
       `;
       const [[existingThreadResult]] = await Promise.all([
         dbQuery(existingThreadQuery),
         dbQuery(deleteRoles),
         dbQuery(deleteIDs),
       ]);
       invariant(existingThreadResult.length > 0, 'thread should exist');
       const existingThreadID = existingThreadResult[0].id.toString();
 
       invariant(request.calendarQuery, 'calendar query should exist');
       const calendarQuery = {
         ...request.calendarQuery,
         filters: [
           ...request.calendarQuery.filters,
           { type: 'threads', threadIDs: [existingThreadID] },
         ],
       };
 
       let joinUpdateInfos = [];
       let userInfos: UserInfos = {};
       let newMessageInfos = [];
       if (threadType !== threadTypes.PERSONAL) {
         const joinThreadResult = await joinThread(viewer, {
           threadID: existingThreadID,
           calendarQuery,
         });
         joinUpdateInfos = joinThreadResult.updatesResult.newUpdates;
         userInfos = joinThreadResult.userInfos;
         newMessageInfos = joinThreadResult.rawMessageInfos;
       }
 
       const { viewerUpdates: newUpdates, userInfos: changesetUserInfos } =
         await getChangesetCommitResultForExistingThread(
           viewer,
           existingThreadID,
           joinUpdateInfos,
           { calendarQuery, updatesForCurrentSession },
         );
       userInfos = { ...userInfos, ...changesetUserInfos };
 
       return {
         newThreadID: existingThreadID,
         updatesResult: {
           newUpdates,
         },
         userInfos,
         newMessageInfos,
       };
     }
   } else {
     const query = SQL`
       INSERT INTO threads(id, type, name, description, creator, creation_time,
         color, parent_thread_id, containing_thread_id, community, depth,
         default_role, source_message)
       VALUES ${[row]}
     `;
     await dbQuery(query);
   }
 
   let initialMemberPromise;
   if (initialMemberIDs) {
     initialMemberPromise = changeRole(id, initialMemberIDs, null, {
       setNewMembersToUnread: true,
     });
   }
   let ghostMemberPromise;
   if (ghostMemberIDs) {
     ghostMemberPromise = changeRole(id, ghostMemberIDs, -1);
   }
 
   const [
     creatorChangeset,
     initialMembersChangeset,
     ghostMembersChangeset,
     recalculatePermissionsChangeset,
   ] = await Promise.all([
     changeRole(id, [viewer.userID], newRoles.creator.id),
     initialMemberPromise,
     ghostMemberPromise,
     recalculateThreadPermissions(id),
   ]);
 
   const {
     membershipRows: creatorMembershipRows,
     relationshipChangeset: creatorRelationshipChangeset,
   } = creatorChangeset;
 
   const {
     membershipRows: recalculateMembershipRows,
     relationshipChangeset: recalculateRelationshipChangeset,
   } = recalculatePermissionsChangeset;
 
   const membershipRows = [
     ...creatorMembershipRows,
     ...recalculateMembershipRows,
   ];
   const relationshipChangeset = new RelationshipChangeset();
   relationshipChangeset.addAll(creatorRelationshipChangeset);
   relationshipChangeset.addAll(recalculateRelationshipChangeset);
 
   if (initialMembersChangeset) {
     const {
       membershipRows: initialMembersMembershipRows,
       relationshipChangeset: initialMembersRelationshipChangeset,
     } = initialMembersChangeset;
     pushAll(membershipRows, initialMembersMembershipRows);
     relationshipChangeset.addAll(initialMembersRelationshipChangeset);
   }
   if (ghostMembersChangeset) {
     const {
       membershipRows: ghostMembersMembershipRows,
       relationshipChangeset: ghostMembersRelationshipChangeset,
     } = ghostMembersChangeset;
     pushAll(membershipRows, ghostMembersMembershipRows);
     relationshipChangeset.addAll(ghostMembersRelationshipChangeset);
   }
 
   const changeset = { membershipRows, relationshipChangeset };
   const { viewerUpdates, userInfos } = await commitMembershipChangeset(
     viewer,
     changeset,
     {
       updatesForCurrentSession,
     },
   );
 
   const initialMemberAndCreatorIDs = initialMemberIDs
     ? [...initialMemberIDs, viewer.userID]
     : [viewer.userID];
   const messageDatas = [];
   if (threadType !== threadTypes.SIDEBAR) {
     messageDatas.push({
       type: messageTypes.CREATE_THREAD,
       threadID: id,
       creatorID: viewer.userID,
       time,
       initialThreadState: {
         type: threadType,
         name,
         parentThreadID,
         color,
         memberIDs: initialMemberAndCreatorIDs,
       },
     });
   } else {
     invariant(parentThreadID, 'parentThreadID should be set for sidebar');
-    if (!sourceMessage || sourceMessage.type === messageTypes.SIDEBAR_SOURCE) {
+    if (!sourceMessage) {
       throw new ServerError('invalid_parameters');
     }
 
     let editedSourceMessage = sourceMessage;
     if (sourceMessageID && sourceMessage.type === messageTypes.TEXT) {
       const editMessageContent = await fetchLatestEditMessageContentByID(
         sourceMessageID,
       );
       if (editMessageContent) {
         editedSourceMessage = {
           ...sourceMessage,
           text: editMessageContent.text,
         };
       }
     }
 
     messageDatas.push(
       {
         type: messageTypes.SIDEBAR_SOURCE,
         threadID: id,
         creatorID: viewer.userID,
         time,
         sourceMessage: editedSourceMessage,
       },
       {
         type: messageTypes.CREATE_SIDEBAR,
         threadID: id,
         creatorID: viewer.userID,
         time,
         sourceMessageAuthorID: sourceMessage.creatorID,
         initialThreadState: {
           name,
           parentThreadID,
           color,
           memberIDs: initialMemberAndCreatorIDs,
         },
       },
     );
   }
 
   if (
     parentThreadID &&
     threadType !== threadTypes.SIDEBAR &&
     (parentThreadID !== genesis.id ||
       threadType === threadTypes.COMMUNITY_OPEN_SUBTHREAD ||
       threadType === threadTypes.COMMUNITY_OPEN_ANNOUNCEMENT_SUBTHREAD)
   ) {
     messageDatas.push({
       type: messageTypes.CREATE_SUB_THREAD,
       threadID: parentThreadID,
       creatorID: viewer.userID,
       time,
       childThreadID: id,
     });
   }
   const newMessageInfos = await createMessages(
     viewer,
     messageDatas,
     updatesForCurrentSession,
   );
 
   return {
     newThreadID: id,
     updatesResult: {
       newUpdates: viewerUpdates,
     },
     userInfos,
     newMessageInfos,
   };
 }
 
 function createPrivateThread(viewer: Viewer): Promise<NewThreadResponse> {
   return createThread(
     viewer,
     {
       type: threadTypes.PRIVATE,
       description: privateThreadDescription,
       ghostMemberIDs: [commbot.userID],
     },
     {
       forceAddMembers: true,
     },
   );
 }
 
 export { createThread, createPrivateThread, privateThreadDescription };