1. When opening Quickbooks Enterprise 13.0 receive the following error "Quickbooks has opened in multi-user mode because at least one other person is using the company file in multi-user mode. To use the file in single-user mode, ask the other user(s) to close the company file. Then, from your file menu choose "Switch to single-user mode.""
2. Then you receive the error "Company file in use. Please wait."
3. Then you receive the following error "Another quickbooks user (Unknown user) is currently performing a task which must finish before you can continue. Quickbooks will continue automatically when the other user's task has completed."
4. These error are typically due to one computer or terminal server session running a utility, for example verify data and the same company file in multi-user mode will be locked out.
5. To mitigate issue, check all terminal server session or computers in the network with a window waiting for user interaction or running verify data. If not able to find utility window, then log off users then log back in and you should be able to access company file again.