"Can't open file" error message

[Anonymous]

I get this error message when trying to open an ArchiCad file created on a different in-office machine, despite the fact that that machine is using same version and same Hotfix. There is a chance the file was created before his Hotfix update, but file will open on his computer, but not others in the office.

Any ideas?

Thanks.

[Anonymous]

If project created/saved on trial version can only be opened on the machine that created/saved the file, need to install keyplug on machine with trial version to save out as a file that can be opened on other machines.

[Anonymous]

Thanks SBoyd, but he was working with a full license when he created the file. I asked him to "Save As" in different versions. AC wouldn't let him save as a .pla, but he was able to save as v.15 and I was able to open that file. Weird.