Kopano WebApp version 188.8.131.529-1 from Kopano b.v. now available in App Center.
In the last Kopano WebApp update, a beta package of Kopano WebApp files was erroneously included in the app repo. Users can use the Files plugin to integrate external file storage in the Kopano web interface.
Kopano has now released a new app version that includes compatible package versions.
To downgrade the wrong packages Kopano has documented the following command in the App Update README: