Thanks for sharing complete details of your concern and what you've done to fix this, @square1 comp.
I understand the significance of accessing your company file for your business and would like to provide further steps to resolve the error you're experiencing.
QuickBooks error codes 6190 and 816 can occur if multiple users use QuickBooks Desktop in multi-user mode or someone else is logged into the company file in single-user mode.
To fix the issue, the first thing we need to do is to ensure that your QuickBooks desktop is updated then rename .ND and .TLG files. Renaming these will not cause you to lose QuickBooks data. These files are automatically re-created when you open your company file.
Here's how:
1. Open the folder that contains your QuickBooks company file.
2. Look for the same file name as your company files but with extensions .ND and .TLG.
a. company_file.qbw.nd.
b. company_file.qbw.tlg.
3. Right-click each file and select Rename. Add the word OLD at the end of each file name (Example: company_file.qbw.nd.OLD).
4. Reopen QuickBooks and try to sign in to your company file.
If the issue persists, download QuickBooks tool hub then run quick fix my program.
Here's how:
1. In the QuickBooks Tool Hub, select Program Problems.
2. Select Quick Fix my Program.
3. Start QuickBooks Desktop and open your data file.
If the previous step fails to resolve the issue, we can try fixing company file and network issues with QuickBooks File Doctor.
Furthermore, you can restart your computers and servers and move your company files to your local hard drive.
If the issue persists, you can refer to this article for additional troubleshooting steps (Proceed to solutions 3-7 under You open the file over a network Fix error -6000 when opening a company file.
The Community is always here to help if you need further assistance with errors -6190 and -816.
