"QuickBooks is unable to open this company file. It may have been opened by another user. You should ask that user to switch to multi-user so you can both use the company file at the same time. The file could also be located in a read-only network folder. If it is, ask your system administrator to make the file is accessible.
The Support site contains information about this type of error and how to resolve the issue. Go to the Support site to view an article about the error. If the article doesn't help you resolve the problem, contact Support for assistance.
Error codes: (-6189, -816)"
This error can usually be corrected by renaming the company file's .TLG file:
1. Make sure that no one has QuickBooks open on the server (check Task Manager)
2. In File Explorer, make sure that you are able to see file extensions (click "View" at the top, check the "File name extensions" box).
3. Navigate to your company file. It will usually be in one of these directories:
If you cannot find your company file location, just open the root of your C drive and search for *.qbw
4. In your company file folder you will see a .qbw file (which is your actual company file) and a .tlg file. Highlight the .tlg file and rename it to .tlg.old.
5. Launch QuickBooks and try opening the company file again.