Sorry this happened to you! 🙁
When Spine crashed when saving/exiting, it would help to grab the spine.log file. If you start Spine again, it overwrites the spine.log file with a new one. The log you posted shows warnings about loading the project, but doesn't show us the crash.
The errors you see when loading a project are integrity checks that Spine does every time a project is loaded. Various bugs may cause such warnings, often they are bugs in older versions and you see the warnings the first time you open with a newer version, but it's possible bugs in the current version could leave a project in a bad state. The warnings are just to let you know that Spine cleaned up the project. You probably want to check to make sure everything is like you want it to be.
It's very unlikely that if Spine crashed while saving a project that it would cause such warnings. It's much more likely that the file would not be readable at all.
Your best bet is to look at the backups folder, as Erikari mentioned. Sorry we can't do more! We'd love to see the crash log. Did you submit it when/if Spine prompted? If so can you drop us a quick email from the address on your Spine account so we can look up the error? You can just include a link to this thread as the email body.
