Unable to write out files from WE Capture (11.1.1.8)

It fails with the error 'Error creating commit document folder' on releasing a batch.

The Document Folder field in Commit profile is configured to a folder on the same server as Capture is running. And the folder is owned by the same user that is running Capture.

Can anyone help? I've tried the full folder name starting in '\' and assumed a path relative to the domain server directory. Neither worked.

I have previously used the commit driver to create the file but now need to write the file directly.

Unfortunately I have to demo this tomorrow so your response is appreciated.