Error when loading MGTools

Question

When I click the MGTools buttons in the shelf tab, it gave me errors like this:

Answer 1

Basically, there are two possible reasons:

1. The autoloading code didn't work, and some codes that MGTools relies on to initialize itself did not get executed when Maya loaded. 
2. The MGTools program files that the buttons were pointing to does not exist anymore, they are either moved, renamed or deleted.

For the problem #1, check out here.

For the problem #2, you might need to reinstall the MGTools.