Came across QuickBooks error 6190 and 816 and don’t know how to fix it? QuickBooks error code 6190, 816 appears when multiple users make an attempt to open the company file in single user mode. It is also seen if there is a discrepancy between the transaction file and the company file. Moreover, the system is not able to accept the changes which could end up in QuickBooks error 6190 and...