The test does not run in the browser
Test connection on a storage mount contacts the target from the PaperOffice servers, not from the computer where the app is open. A NAS that answers only on the local network at an address such as 192.168.x.x is not reachable for PaperOffice. The test ends with host unreachable, timeout, or connection refused.
Path in the app: Document AI → Storage mounts → Create. Direct: /{lang}/document-ai/storage-mounts-overview.
What BYOS requires
Use as BYOS storage allows external SFTP only. PaperOffice then needs:
- a hostname or a public IP, not a LAN-only address
- the SSH port, default 22, open from the outside to the NAS
- user and password (not an SSH key)
- a dedicated base folder
Create the mount: How do I connect a NAS as a storage mount?.
When port forwarding is not possible
An import source can use Connect local folder via Reverse-SSH. The site opens an outbound tunnel to PaperOffice (r-ssh.paperoffice.ai, port 443). Inbound port forwarding is not required. In the dialog, enter the local SSH user and the local folder. The dialog then shows the setup commands to copy.
Reverse-SSH is not a BYOS connection. If originals should stay on the NAS and the workspace should write there, reachable SFTP remains the requirement.
Test error texts: Connection test failed.