You can implement the following methods to resolve QUICKBOOKS Error 6210, 0 error:

Method 2: Perform Manual Updates
• Double-click ‘cmd.exe’ after selecting the Startup option and typing ‘cmd’ in the search box.
• Now type GP update in the box provided and press Enter, after which the malware will be removed.

Method 3: For issue caused due to virus attack
• Select the Startup option, type cmd in the search box, and then double-click cmd.exe.
• Now type GP update in the box provided and press Enter, after which the malware will be removed.

Method 4: Terminate Conflicting Programs
• Keep in mind that runtime errors are caused by incompatible programs.
• To access Task Manager, press the 'Ctrl+Alt+Del' keys simultaneously. This will display a list of currently running programs.
• Go to the Processes tab and, one by one, halt the programs by highlighting them and selecting the 'End Process' option.
• After you halt a process, keep a watch on whether the error notice shows again.
• Once you've determined which program is causing the error, you may move on to the next troubleshooting step, which is reinstalling the application.

Read more: https://qbsenterprisesupport.com/quickbooks-error-6210-0/