I can place a file into the directory manually, but when I try to do this from another server it fails. Is this being restricted as it is the free addition?

No, there is no such restriction. Please provide more detailed info about which software you use, how you upload and which folder/file is having this problem.

If you use WebDAV Cloud Drive Mapping Tool, you can click Advanced -> Event Log -> Send Event Log to Support. 

If you use DriveHQ FileManager, you can click Help -> Send Event Log To Support

Please email us the steps to duplicate your problem.