Unity 8 Compatibility error when opening .stu files

Hi,

I have multiple PCs with Unity Pro XL 8 installed. I am getting an error on one PC when I open an stu file that was created on another PC.

It says
"Project file not compatible:
Please open archive file (STA) to ensure the compatibility or import file (ZEF, XEF).
Remark: the import will need a full rebuild."

Does anybody know how I can ensure that I don't have this issue when opening STU files on multiple PCs? STAs take a long time to open.

I don't really know what the criteria for this compatibility is. The machines have been installed by the same installation files...

Thanks!

the only way that error can happen is if the 2 pc's are running 2 different versions of unity.

I would probably reinstall Unity on the pc that is coming up with the compatibility error
PS it is a good idea to save an .sta file in addition to the .stu file then if you need to open a program with a different version you can

replace .stu with .sta