diff --git a/app/server/lib/FlexServer.ts b/app/server/lib/FlexServer.ts
index 277d671e..76667642 100644
--- a/app/server/lib/FlexServer.ts
+++ b/app/server/lib/FlexServer.ts
@@ -1999,9 +1999,15 @@ export class FlexServer implements GristServer {
     const userRoot = path.resolve(process.env.GRIST_USER_ROOT || getAppPathTo(this.appRoot, '.grist'));
     this.info.push(['userRoot', userRoot]);
     // Some custom widgets may be included as an npm package called @gristlabs/grist-widget.
+    // The package doesn't actually  contain node code, but should be in the same vicinity
+    // as other packages that do, so we can use require.resolve on one of them to find it.
+    // This seems a little overcomplicated, but works well when grist-core is bundled within
+    // a larger project like grist-electron.
+    // TODO: maybe add a little node code to @gristlabs/grist-widget so it can be resolved
+    // directly?
+    const gristLabsModules = path.dirname(path.dirname(require.resolve('@gristlabs/express-session')));
     const bundledRoot = isAffirmative(process.env.GRIST_SKIP_BUNDLED_WIDGETS) ? undefined : path.join(
-      getAppPathTo(this.appRoot, 'node_modules'),
-      '@gristlabs', 'grist-widget', 'dist'
+      gristLabsModules, 'grist-widget', 'dist'
     );
     this.info.push(['bundledRoot', bundledRoot]);
     const pluginManager = new PluginManager(this.appRoot, userRoot, bundledRoot);
diff --git a/app/server/lib/WidgetRepository.ts b/app/server/lib/WidgetRepository.ts
index f79a049f..d94ed92b 100644
--- a/app/server/lib/WidgetRepository.ts
+++ b/app/server/lib/WidgetRepository.ts
@@ -4,7 +4,7 @@ import * as fse from 'fs-extra';
 import fetch from 'node-fetch';
 import * as path from 'path';
 import {ApiError} from 'app/common/ApiError';
-import {removeTrailingSlash} from 'app/common/gutil';
+import {isAffirmative, removeTrailingSlash} from 'app/common/gutil';
 import {GristServer} from 'app/server/lib/GristServer';
 import LRUCache from 'lru-cache';
 import * as url from 'url';
@@ -96,7 +96,8 @@ export class CombinedWidgetRepository implements IWidgetRepository {
  * Repository that gets a list of widgets from a URL.
  */
 export class UrlWidgetRepository implements IWidgetRepository {
-  constructor(private _staticUrl = STATIC_URL) {}
+  constructor(private _staticUrl = STATIC_URL,
+              private _required: boolean = true) {}
 
   public async getWidgets(): Promise<ICustomWidget[]> {
     if (!this._staticUrl) {
@@ -126,10 +127,16 @@ export class UrlWidgetRepository implements IWidgetRepository {
       fixUrls(widgets, this._staticUrl);
       return widgets;
     } catch (err) {
-      if (!(err instanceof ApiError)) {
-        throw new ApiError(String(err), 500);
+      if (this._required) {
+        if (!(err instanceof ApiError)) {
+          throw new ApiError(String(err), 500);
+        }
+        throw err;
+      } else {
+        log.error("WidgetRepository: Error fetching widget list - " +
+            String(err));
+        return [];
       }
-      throw err;
     }
   }
 }
@@ -177,7 +184,9 @@ export class WidgetRepositoryImpl implements IWidgetRepository {
     const repos: IWidgetRepository[] = [];
     this._staticUrl = overrideUrl ?? STATIC_URL;
     if (this._staticUrl) {
-      this._urlWidgets = new UrlWidgetRepository(this._staticUrl);
+      const optional = isAffirmative(process.env.GRIST_WIDGET_LIST_URL_OPTIONAL);
+      this._urlWidgets = new UrlWidgetRepository(this._staticUrl,
+                                                 !optional);
       repos.push(this._urlWidgets);
     }
     if (this._diskWidgets) { repos.push(this._diskWidgets); }