Max on 03 Jan, 2019 09:32 PM
Sorry to hear about this issue. Sounds like the file must have been majorly corrupted, not sure what the cause. The history menu normally can cure this, as it makes a copy every time time you open and close the file. Not sure what happened in this case however. Wish I could do more to help.
Glad to know you like the app! In the next few updates we'll try to get rid of some of these pesky crashes.