How do I revert to a previous version of TC?

Seemingly object recognition. It's running slow and then failing. 
I am seeing these errors:

The window with the handle 0x00000000 does not exist.

This error occurred when the tested window (or control) or its parent object was deleted or recreated right before the method call. For example, you stored a window reference to a variable and then called a method through this variable.
If the object has been recreated, then to avoid the error, get the new object before the method call.