InCopy problems in publishing workflow

Trying to diagnose problems with InCopy. Work for small publishing co. with about 6 people in team - proofer, editors, designers. One designer's computer was recently wiped and all Adobe CC 2017 programs were reinstalled. Since that time, had many probs with InCopy files not opening and crashing program. The machine was upgraded to MacOS High Sierra, where the rest of the team is still on the original Sierra. Could this be the culprit? Don't have any other ideas as to why problems keep[ happening.

Thanks.