If you are facing QuickBooks error code 6190 while using the company file, then you can perform a single-user mode check with the help of the following steps:

• First of all, check if all the users are logged out of the QB application.

• Then, reboot your systems.

• Now, you need to move your data file to your desktop or any other location, so copy it. 

• After this, you have to copy your data file again to its original location.

• Lastly, end the process by signing into QB and accessing the company file.