message: reintroduce check that provider is not null
diff: @@ -87,6 +87,9 @@ export function AppThemeProvider({ children }: PropsWithChildren<{}>) {
  if (!appTheme) {
  throw new Error('App has no themes');
  }
  + if (!appTheme.Provider) {
  + throw new Error('App has no theme provider');
  + }
  return <appTheme.Provider children={children} />;
  }
  