Just my observation (I am just another user), there is a temporary file going that is a combination of RAM and space on your hard drive. It is within the project folder where project specific resources are stored. It is not committed to the hard drive until you save it. It is a backup file with the same name but it has a tilda ~ at the end.
Custom presets like brushes you might have made are probably OK because you save them immediately when you create them. They are buried in application sub-folders and are not limited to a single project. I have dug the custom files out to transfer them to a new installation after a crash.
There is a chance that the temp file remained on the hard drive but it may be corrupt.
If you see it in the folder make a copy calling it something like “project name_____-copy” then remove the tilda before trying to open the temp file. I would not attempt to work with the original. I would make a copy, rename the original adding “-orig” to its name then change the copy to match the unaltered original file name and try opening the copy with the tilda removed.
(I know it’s a convoluted description, hopefully you can understand what I am describing)
The objective is to preserve the original. Experiment with the copy. You can make more copies from the original just in case you need to.