After pkg update (and truenas update) error: Application [...] is not present or has a non-compatible version with this server. Please check the apps directory

Hi. I got this error message after an update of truenas (13.U3 to 13.U5). I checked the directory and permission of …/apps-pkg but cannot see anything suspect.
any idea where to start with this errormessage?
thanks a lot!

and its nextcloud 27…