There is an error in the log similar to this:
This comes directly from the Intuit Software Development Kit (SDK) and indicates that it is unable to continue, because it sees two instances of QBW32.EXE running.
This includes running a second instance of QuickBooks while the synch with another file is running - including different versions of QuickBooks.
Make sure that only one instance of QuickBooks is running when attempting a synch. If you are uncertain, run the Task Manager to ensure that another instance of QBW32.EXE is not running
is requesting access to a wiki that you have locked: https://clearify.com/wiki/view/3696/error-80040438-multiple-quickbooks-running