Just tried opening my second account and this is the last line in activity monitor “open files and ports” for me:
134
/private/var/folders/7h/j4w8kstj6_1fg7pm0lpx6t2w0000gn/T/WoW ASYNCTHREADSHAREDMEM.1.mutex
So not line 127, however it is that same temporary file. Deleting the suggested files allows me to launch my second account.
Thanks for the find, Bheleu!
Also as a note, I have NOT tried the other temporary solutions in the thread such as the “reopen windows on restart” or PRAM/NVRAM reset. So this “delete temp file” solution works WITHOUT having done anything else.