Access to container field content

[GC GYM]

Using 'store only a reference', I have put some files (references) into container fields.

Some of the documents are on the local machine, some are on a mapped drive on a remote server.

Access via Filemaker Go works fine.

Access via Filemaker Pro is inconsistent. On some machines it works, on others nothing happens when you double click the field. Mac/Windows both work and don't work. Local Machine, LAN, WAN or remote server works and doesn't work.

Any suggestions?