Affinity Designer 1.8.1 told me it could not save my file because of an internal error and that I should contact the developer.
I thought: no big deal, as I didn't really change anything. I closed affinity and double clicked my affinity file and then I saw
that the file was 0 bytes. Basicly Affinity Designer destroyed the file. I lost a lot of work. But it is my fault, I should have
known better and take backups.
The mac just came back from sleep, Affinity Designer has been open sinds the 1.8.1 update,
never closed it, and that destroyed document was also open since then.
If you need more information to debug this issue, I'm heppy to help, I'm a developer myself so I have the technical skills to
provide you whatever you need to solve this issue.