diff --git a/src/Logic/State/UserRelatedState.ts b/src/Logic/State/UserRelatedState.ts
index e496a4067..8ca36200a 100644
--- a/src/Logic/State/UserRelatedState.ts
+++ b/src/Logic/State/UserRelatedState.ts
@@ -350,10 +350,10 @@ export default class UserRelatedState {
      * List of all hidden themes that have been seen before
      * @param osmConnection
      */
-    public static initDiscoveredHiddenThemes(osmConnection: OsmConnection): Store<string[]> {
+    public static initDiscoveredHiddenThemes(osmConnection: OsmConnection): Store<undefined | string[]> {
         const prefix = "mapcomplete-hidden-theme-"
         const userPreferences = osmConnection.preferencesHandler.allPreferences
-        return userPreferences.map((preferences) =>
+        return userPreferences.mapD((preferences) =>
             Object.keys(preferences)
                 .filter((key) => key.startsWith(prefix))
                 .map((key) => key.substring(prefix.length, key.length - "-enabled".length))
diff --git a/src/UI/AllThemesGui.svelte b/src/UI/AllThemesGui.svelte
index ae30a0c56..14c38a216 100644
--- a/src/UI/AllThemesGui.svelte
+++ b/src/UI/AllThemesGui.svelte
@@ -40,7 +40,7 @@
   const tu = Translations.t.general
   const tr = Translations.t.general.morescreen
 
-  let userLanguages = osmConnection.userDetails.map((ud) => ud.languages)
+  let userLanguages = osmConnection.userDetails.map((ud) => ud?.languages ?? [])
   let search: UIEventSource<string | undefined> = new UIEventSource<string>("")
   let searchStable = search.stabilized(100)
 
@@ -52,12 +52,12 @@
   const hiddenThemes: MinimalThemeInformation[] = ThemeSearch.officialThemes.themes.filter(
     (th) => th.hideFromOverview === true
   )
-  let visitedHiddenThemes: Store<MinimalThemeInformation[]> =
-    UserRelatedState.initDiscoveredHiddenThemes(state.osmConnection).map((knownIds) =>
+  let visitedHiddenThemes: Store<undefined | MinimalThemeInformation[]> =
+    UserRelatedState.initDiscoveredHiddenThemes(state.osmConnection).mapD((knownIds) =>
       hiddenThemes.filter(
         (theme) =>
           knownIds.indexOf(theme.id) >= 0 ||
-          state.osmConnection.userDetails.data.name === "Pieter Vander Vennet"
+          state.osmConnection.userDetails?.data?.name === "Pieter Vander Vennet"
       )
     )
 
@@ -67,6 +67,9 @@
   function filtered(themes: Store<MinimalThemeInformation[]>): Store<MinimalThemeInformation[]> {
     return searchStable.map(
       (search) => {
+        if (!themes.data) {
+          return []
+        }
         if (!search) {
           return themes.data
         }