Archiving Errot "Invalid response"


we have since some time the following error when running the cronjob for archiving:

"Got invalid response from API request: ?module=API&method=CoreAdminHome.archiveReports&idSite=11&period=year&date=2022-01-01&format=json& Response was '{“result”:“error”,“message”:"Trying to sum unsupported operands for column segment in row with label = datatable_metadata: string + integer - in plugin Referrers. #0 "

I have tried to find the entry or the data type, unfortunately without success, because I don’t really know in which table I have to search. Does anyone know how to fix this error?