Collabora tried to open or save a document and the document’s ZIP stream was incomplete or corrupt — the file content it received didn’t match the file’s own internal structure.
If you can share the log lines immediately before this CALLBACK_ERROR (the WOPI request/transfer entries for the same session), I can help pin down whether it’s a broken transfer or an actually corrupt document.
This is a sensitive topic only in the sense of data integrity — if it turns out to be a corrupt file, the user may have lost recent edits, so it’s worth checking whether a prior good version exists in the storage backend’s version history.
Those lines are the root cause: coolmount: Operation not permitted means your Docker container can’t perform mount operations. That kills the background save process mid-write, so the document stream comes out truncated — which is exactly what the zipapi “stream seems to be broken” error is complaining about. Your files in storage are most likely fine.
Fix: run the container with --cap-add MKNOD --cap-add SYS_ADMIN (compose: cap_add: [MKNOD, SYS_ADMIN]). If you’re on rootless Docker or a NAS where mounts aren’t possible, add -e "extra_params=--o:mount_jail_tree=false" instead.
