According to Intuit, Error Code -6000, -77 is an error that can occur when attempting to open a company file.
There are several possible causes for this error:
- the company file is located on external media rather than a local or network drive
- QuickBooks is attempting to open the company file by referencing a mapped drive
- BitDefender security software is blocking communication when running QuickBooks in multi-user mode
- incorrect folder permissions on the folder in which the company file is located
To follow the troubleshooting steps to resolve Error Code -6000, -77, consult this Intuit knowledge base article.