According to Intuit, error code 6176 means that QuickBooks couldn’t resolve the path to the company file (.qbw).
To resolve this error, start the QuickBooks Database Server Manager on the computer where the company file is located and click the Scan Folders tab. Click the Add Folder… button to add the folders where QuickBooks company files are located. If you’re not sure where these files are located, select the entire disk. When the scan is complete, click the Close button.
For more information on this error code, consult this Intuit knowledge base article.