I'm having same problem, however I have installed Feng Office using Synology disc station. I can do almost everything using Feng Office (create files, download created documents, etc..) But I cannot upload any document on the server. I'm going to 'documents', then clicking '+', choosing file. But finally I have an information "Success: File '' has been added", but the file is not uploaded. The file size is 8kb.
regards
GC