HELP File won't open - has it corrupted?

Hi, I have created a 36pp document as spreads (18 pages) in Corel Draw X8, on my windows 10 HP laptop. I then have spent time cutting and pasting all the pages into a new file to create a 36pp document. I have done this twice and for some reason the new document won't open, it keeps crashing Corel Draw, and won't tell me why? Both files are 120mb, but the spread document opens fine.