I installed fresh on my Raspberry Pi 4 4GB model. I am using 32-bit raspberry pi os lite and used Nextcloud’s official docker image. I logged in went to open the “Welcome to Nextcloud.docx” file and got the error “Document loading failed. Nextcloud office not configured.” I have checked in apps and it is installed, my cache and cookies have been cleared.
SIDE NOTE: other supported files work, such as .md, with a working editor.