You can experience QuickBooks Error Code 6000 when you are trying to launch the QuickBooks program on your device. The error can occur due to various reasons that are mentioned below:
When the TLG file gets damaged
Faulty QuickBooks installation
Your device’s firewall or antivirus is blocking the connection
Your QuickBooks company file is damaged
There are multiple users logged into your company file
The issue is with your network connection
To fix the error, we suggest you work on the above causes and try running the QuickBooks program again. Also, you can try opening your company file into a new location or rename the .ND and .TLG files.