Did you both verify local files, and make sure you have the latest/same version?
Please email supportdos@larian.com, with a description of the problem and the report.zip file generated by the
D:OS support tool (for the PC version) for both computers. The report will contain system and network information which should help Larian track down the problem.
The report also contains the save files; since they are not directly relevant in this case, you can delete most of them if file size is an issue.
