Quickbooks 2011 error 6189 and 816 is a runtime error that a user may get at the time of trying to open (.QWB) file or at the time while trying to run QB desktop on a multi-user network. This error may appear when you try to access a QB file that is being used by someone else at the same time.
https://mathomatic.org/quickbooks-error-6189-and-816/