Problem with Foris across versions 100.3-100.5 An unexpected error has occurred

From version 100.3 I have problem with the Foris/notifications tab does not work. (An unexpected error has occurred). All other tab are working. Upgrade does not help there must be an error somewhere in the config files. Turris support did not find a reason… Do you have any idea how to reset the Foris app? I tried uninstalling, and installing the Foris but did not help. I would not like to solve a factory reset MOX. Its last solutions.