diff --git a/src/Lifecycle.ts b/src/Lifecycle.ts
index b6fce3b6365..3e87541ddd6 100644
--- a/src/Lifecycle.ts
+++ b/src/Lifecycle.ts
@@ -19,7 +19,6 @@ limitations under the License.
 
 import { ReactNode } from "react";
 import { createClient, MatrixClient, SSOAction, OidcTokenRefresher } from "matrix-js-sdk/src/matrix";
-import { InvalidStoreError } from "matrix-js-sdk/src/errors";
 import { IEncryptedPayload } from "matrix-js-sdk/src/crypto/aes";
 import { QueryDict } from "matrix-js-sdk/src/utils";
 import { logger } from "matrix-js-sdk/src/logger";
@@ -52,8 +51,6 @@ import LegacyCallHandler from "./LegacyCallHandler";
 import LifecycleCustomisations from "./customisations/Lifecycle";
 import ErrorDialog from "./components/views/dialogs/ErrorDialog";
 import { _t } from "./languageHandler";
-import LazyLoadingResyncDialog from "./components/views/dialogs/LazyLoadingResyncDialog";
-import LazyLoadingDisabledDialog from "./components/views/dialogs/LazyLoadingDisabledDialog";
 import SessionRestoreErrorDialog from "./components/views/dialogs/SessionRestoreErrorDialog";
 import StorageEvictedDialog from "./components/views/dialogs/StorageEvictedDialog";
 import { setSentryUser } from "./sentry";
@@ -439,39 +436,6 @@ async function onFailedDelegatedAuthLogin(description: string | ReactNode, tryAg
     });
 }
 
-export function handleInvalidStoreError(e: InvalidStoreError): Promise<void> | void {
-    if (e.reason === InvalidStoreError.TOGGLED_LAZY_LOADING) {
-        return Promise.resolve()
-            .then(() => {
-                const lazyLoadEnabled = e.value;
-                if (lazyLoadEnabled) {
-                    return new Promise<void>((resolve) => {
-                        Modal.createDialog(LazyLoadingResyncDialog, {
-                            onFinished: resolve,
-                        });
-                    });
-                } else {
-                    // show warning about simultaneous use
-                    // between LL/non-LL version on same host.
-                    // as disabling LL when previously enabled
-                    // is a strong indicator of this (/develop & /app)
-                    return new Promise<void>((resolve) => {
-                        Modal.createDialog(LazyLoadingDisabledDialog, {
-                            onFinished: resolve,
-                            host: window.location.host,
-                        });
-                    });
-                }
-            })
-            .then(() => {
-                return MatrixClientPeg.safeGet().store.deleteAllData();
-            })
-            .then(() => {
-                PlatformPeg.get()?.reload();
-            });
-    }
-}
-
 function registerAsGuest(hsUrl: string, isUrl?: string, defaultDeviceDisplayName?: string): Promise<boolean> {
     logger.log(`Doing guest login on ${hsUrl}`);
 
diff --git a/src/components/structures/MatrixChat.tsx b/src/components/structures/MatrixChat.tsx
index b9ac2c71d72..d775059c319 100644
--- a/src/components/structures/MatrixChat.tsx
+++ b/src/components/structures/MatrixChat.tsx
@@ -27,7 +27,6 @@ import {
     SyncStateData,
     SyncState,
 } from "matrix-js-sdk/src/matrix";
-import { InvalidStoreError } from "matrix-js-sdk/src/errors";
 import { defer, IDeferred, QueryDict } from "matrix-js-sdk/src/utils";
 import { logger } from "matrix-js-sdk/src/logger";
 import { throttle } from "lodash";
@@ -1484,9 +1483,6 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
 
         cli.on(ClientEvent.Sync, (state: SyncState, prevState: SyncState | null, data?: SyncStateData) => {
             if (state === SyncState.Error || state === SyncState.Reconnecting) {
-                if (data?.error instanceof InvalidStoreError) {
-                    Lifecycle.handleInvalidStoreError(data.error);
-                }
                 this.setState({ syncError: data?.error ?? null });
             } else if (this.state.syncError) {
                 this.setState({ syncError: null });
@@ -2018,14 +2014,10 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
                 />
             );
         } else if (this.state.view === Views.LOGGED_IN) {
-            // store errors stop the client syncing and require user intervention, so we'll
-            // be showing a dialog. Don't show anything else.
-            const isStoreError = this.state.syncError && this.state.syncError instanceof InvalidStoreError;
-
             // `ready` and `view==LOGGED_IN` may be set before `page_type` (because the
             // latter is set via the dispatcher). If we don't yet have a `page_type`,
             // keep showing the spinner for now.
-            if (this.state.ready && this.state.page_type && !isStoreError) {
+            if (this.state.ready && this.state.page_type) {
                 /* for now, we stuff the entirety of our props and state into the LoggedInView.
                  * we should go through and figure out what we actually need to pass down, as well
                  * as using something like redux to avoid having a billion bits of state kicking around.
@@ -2042,12 +2034,11 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
                 );
             } else {
                 // we think we are logged in, but are still waiting for the /sync to complete
-                // Suppress `InvalidStoreError`s here, since they have their own error dialog.
                 view = (
                     <LoginSplashView
                         matrixClient={MatrixClientPeg.safeGet()}
                         onLogoutClick={this.onLogoutClick}
-                        syncError={isStoreError ? null : this.state.syncError}
+                        syncError={this.state.syncError}
                     />
                 );
             }
diff --git a/src/components/views/dialogs/LazyLoadingDisabledDialog.tsx b/src/components/views/dialogs/LazyLoadingDisabledDialog.tsx
deleted file mode 100644
index 1e90b91b455..00000000000
--- a/src/components/views/dialogs/LazyLoadingDisabledDialog.tsx
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
-Copyright 2018 New Vector Ltd
-Copyright 2020 The Matrix.org Foundation C.I.C.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-import React from "react";
-
-import QuestionDialog from "./QuestionDialog";
-import { _t } from "../../../languageHandler";
-import SdkConfig from "../../../SdkConfig";
-
-interface IProps {
-    host: string;
-    onFinished(): void;
-}
-
-const LazyLoadingDisabledDialog: React.FC<IProps> = (props) => {
-    const brand = SdkConfig.get().brand;
-    const description1 = _t("lazy_loading|disabled_description1", {
-        brand,
-        host: props.host,
-    });
-    const description2 = _t("lazy_loading|disabled_description2", {
-        brand,
-    });
-
-    return (
-        <QuestionDialog
-            hasCancelButton={false}
-            title={_t("lazy_loading|disabled_title")}
-            description={
-                <div>
-                    <p>{description1}</p>
-                    <p>{description2}</p>
-                </div>
-            }
-            button={_t("lazy_loading|disabled_action")}
-            onFinished={props.onFinished}
-        />
-    );
-};
-
-export default LazyLoadingDisabledDialog;
diff --git a/src/components/views/dialogs/LazyLoadingResyncDialog.tsx b/src/components/views/dialogs/LazyLoadingResyncDialog.tsx
deleted file mode 100644
index 54779bda4c6..00000000000
--- a/src/components/views/dialogs/LazyLoadingResyncDialog.tsx
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
-Copyright 2018 New Vector Ltd
-Copyright 2020 The Matrix.org Foundation C.I.C.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-import React from "react";
-
-import QuestionDialog from "./QuestionDialog";
-import { _t } from "../../../languageHandler";
-import SdkConfig from "../../../SdkConfig";
-
-interface IProps {
-    onFinished(): void;
-}
-
-const LazyLoadingResyncDialog: React.FC<IProps> = (props) => {
-    const brand = SdkConfig.get().brand;
-    const description = _t("lazy_loading|resync_description", { brand });
-
-    return (
-        <QuestionDialog
-            hasCancelButton={false}
-            title={_t("lazy_loading|resync_title", { brand })}
-            description={<div>{description}</div>}
-            button={_t("action|ok")}
-            onFinished={props.onFinished}
-        />
-    );
-};
-
-export default LazyLoadingResyncDialog;
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index 3cebc61cae2..65e5accef82 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -1511,14 +1511,6 @@
         "view_rules": "View rules"
     },
     "language_dropdown_label": "Language Dropdown",
-    "lazy_loading": {
-        "disabled_action": "Clear cache and resync",
-        "disabled_description1": "You've previously used %(brand)s on %(host)s with lazy loading of members enabled. In this version lazy loading is disabled. As the local cache is not compatible between these two settings, %(brand)s needs to resync your account.",
-        "disabled_description2": "If the other version of %(brand)s is still open in another tab, please close it as using %(brand)s on the same host with both lazy loading enabled and disabled simultaneously will cause issues.",
-        "disabled_title": "Incompatible local cache",
-        "resync_description": "%(brand)s now uses 3-5x less memory, by only loading information about other users when needed. Please wait whilst we resynchronise with the server!",
-        "resync_title": "Updating %(brand)s"
-    },
     "leave_room_dialog": {
         "last_person_warning": "You are the only person here. If you leave, no one will be able to join in the future, including you.",
         "leave_room_question": "Are you sure you want to leave the room '%(roomName)s'?",