QuickBooks Error 6190 is an error that occurs when multiple users are trying to access the company file in single-user mode or due to a mismatch between the transaction log file (.TLG) and the company file (.QBW). Here are some steps you can follow to resolve QuickBooks Error 6190:

Open the company file locally:

Copy the company file (.QBW) to your local desktop or the computer where QuickBooks is installed.

Open QuickBooks on that computer and then open the company file from the local location.

Switch to multi-user mode:

Go to the File menu in QuickBooks and select "Switch to Multi-User Mode."

If you get a prompt asking if you want to close all open windows, choose Yes.

Copy the company file back to its original location and try accessing it in multi-user mode.

Use the QuickBooks File Doctor:

Download and run the QuickBooks File Doctor tool from the Intuit website.

Follow the on-screen instructions to scan and repair the company file. The tool will automatically fix the error if it finds any issues.

Rename the transaction log file and restart QuickBooks Database Server Manager:

Open the folder where your company file is located.

Locate the transaction log file (file with the .TLG extension) that has the same name as your company file.

Right-click on the transaction log file and select "Rename." Add the word "OLD" at the end of the filename.

Restart the QuickBooks Database Server Manager:

Close QuickBooks on all computers.

Go to the Start menu and search for "Services."

Open the Services window and find the QuickBooksDBXX service (XX represents the version of QuickBooks).

Right-click on the QuickBooksDBXX service and select Restart.

Open QuickBooks and try opening the company file again.

Copy the company file to a new location:

Create a new folder on your local desktop or the computer where QuickBooks is installed.

Copy the company file (.QBW) and the transaction log file (.TLG) to the new folder.

Open QuickBooks and try opening the company file from the new location.

Use Auto Data Recovery (ADR) tool:

If the above steps do not resolve the error, you can try using the Auto Data Recovery (ADR) tool provided by Intuit. This tool helps recover and repair damaged company files. Refer to the QuickBooks support website or contact QuickBooks Support for more information on using the ADR tool.

Greetings,
Peter