OpenOffice document security token not correctly formed

Dear Community,

Users recently reported an error that appears on any Office documents with the repository: trying to open any doc (xls, xlsx, doc, docx, ppt, pptx) brings up an error message saying that the “document security token is not correctly formed. Please contact your Document Server administrator.” (see below, sorry for the French).

Capture d'écran_20230301_181459

Context

  • Nextcloud: v25.0.4
  • OnlyOffice: v7.6.8
  • No core update, only secondary applications (i.e. Dashboard or External storage support)

Found some posts talking about JWT tokens, but didn’t understand what to do not where to look for local.json file, which seems to be part of the problem.

Could anyone help on this issue? Should I better post on OnlyOffice forum? The repository is just useless today…

Thanks in advance for any help!