Donald - shot in the blue, trash prefs (better, ZIP/archive prefs), and try again. Sometimes starting with fresh prefs solves issues.
https://dcpomatic.com/faq?id=23
DCP-o-matic Crashes Continuously
Re: DCP-o-matic Crashes Continuously
It might also be interesting if you could somehow send me one of the files you are adding (to cause the crashes).