(SOLVED)Update: installed onlyoffice-10.0.0

We are back to stable and everything appears to be fine.

(SOLVED)Update: installed onlyoffice-10.0.0-beta

Installed new beta and applied patch. Onlyoffice seems to work again.

Update: installed netcloud-office as workaround

As a workaround I have installed an alternative office back- and frontend (which is less performant, plus you have to explicitely press save to save the document).

onlyoffice does not work after nextcloud update

Office plugin is temporarily disabled, since it prevents preview of files and renders the whole nextcloud unusable.