Cannot upload via web or desktop client (Windows)

Seafile 6.2.2
Ubuntu 16.04

I uploaded one 571 Gb file, a smaller 499 Gb file is failing with “Unknown error”. Desktop client is failing with “Failed to upload file: Unable to write”

Sometimes the uploading fails without starting and debug console in Chrome shows 500 Server Error, sometimes it fails while uploading (at exactly 16% or 84.7 Mb) and there is nothing in the logs. Chrome just reports “ERR_CONNECTION_RESET”, failed to load resource.

The hard drives have sufficient space.

seahub_django_request.log shows this: NetworkError: Failed to write to socket: [Errno 32] Broken pipe

seahub.log shows: [ERROR] seahub.api2.endpoints.repo_file_uploaded_bytes:52 get ‘SeafileAPI’ object has no attribute ‘get_upload_tmp_file_offset’

Is there a way to enable some kind of additional logging? I have no idea why the upload is failing and I cannot find much guidance on these errors by searching the forum.