I've been hitting this assertion on shutdown frequently this week. The assertion was added a few months ago in bug 458091, but I'm only hitting it now. I have browser.sessionstore.resume_from_crash set to false, in case that matters. ###!!! ASSERTION: GetSessionStorageForPrincipal got a storage that could not be accessed!: 'canAccess', file /Users/jruderman/central/docshell/base/nsDocShell.cpp, line 2200

I was going to suggest that this was caused by bug 494543, but it hasn't landed yet. Might be related, though.

This assert firing scares me. A lot.

Any further information how to reproduce this? Would be great to call DumpJSStack() in gdb from xpc3250.so context (e.g. XPCWrappedNative::CallMethod frame) to get JS callstack or at least know what pages were open during exit.

I was able to get this assertion during shutdown. It's quit likely it's this bug. JS stack shows this bug is duplicate of bug 494543.

Sorry, mid-air turned the b191 flag back to ?. I don't have permissions to make it blocking again...

No longer hitting this now that bug 494543 is fixed :)

No need to ask for blocking on a dupe.