Others seem to be reporting something similar, but my issues has some specifics that may help track down the trouble. Here it is:
Situation: I have a Mac mini running 10.11 (never had the beta version) but do almost all my writing on an old MacBook running the last version it will run, 10.7.5. I synch documents with Dropbox. The problem is with the MacBook and 10.7.5. The Mac mini gives me a workaround that those who have a single, older Mac won’t have.
The problem develops this way.
Scrivener on MacBooks crashes. I suspect that’s due to some HTML documents I have in my Research folder but that’d not the real issue.
When I reopen that document on my MacBook, I get a CrashReporter window and the spinning rainbow wheel. To escape, I have to force quit Scrivener. Waiting fifteen minutes for the spinning to stop made no difference.
That leaves me in a trap, every effort to open that document or any other gives me that CrashReporter window and spinning wheel.
The problem can be fixed this way.
Via Dropbox, I open the document in Scrivener on my Mac mini and 10.11. When it opens, I get a message that the document is open elsewhere. I agree to let Scrivener create another file. I then slightly edit and save that new document and close it.
On my MacBook, I open that new version. Scrivener gives me the CrashReporter window but this time does not lock up. That looks suspiciously like under 10.7.5 Scrivener is writing a defective crash report. I send the crash report and then I can edit the document. The problem is fixed until my next Scrivener crash for other reasons.
Additional factor. Eliminating the files in Library/CrashReporter on my MacBook makes no difference. Since Scrivener still knows there was a crash, there are probably other files I don’t know about and thus can’t trash.
Hope that helps track this pesky beast down.