Are you using the latest version? If you are and it's still happening it would be great if you could upload a file where this is happening. Ideally by making a new issue on https://github.com/OpenRCT2/OpenRCT2/issues but if you're just uploading here that's useful too.
Sorry for a late response but the crashing was caused by the custom ride The Zap - it crashes the game when it unloads peeps. I filed a bug report although I'm not sure if it's just a bug in the ride itself.