Some QuickBooks Desktop users may be prompted with a message “Application cannot be started. Contact the application vendor.” See image below.

1. Completely shut down the Sync Engine.

2. In Windows, navigate to the folder:

Note: In the folder address, username will appear as the name of the Windows user (as in our example below).

3. Rename the 2.0 folder (choose a name that makes sense for you).

4. Run the Method Sync Engine. This will recreate the folder you renamed above.

At this point, the sync engine should run properly.

If Solution 1 does not work for you, your antivirus program may be conflicting with the sync engine.

1. Uninstall the Method Sync Engine.

2. Disable your antivirus program.

3. Turn off the Windows Defender Firewall.

Control Panel -> System & Security -> Windows Defender Firewall -> Turn Windows Defender Firewall on or off.

4. Reinstall the Method Sync Engine.

5. Re-enable your antivirus program.

At this point, the sync engine should run properly.