UI buttons and drag drop no longer responding

All of my UI buttons and all drag and drop objects are not longer working. I can see that the button is pressed, but the link to the script file does not execute. None of the drag and drop objects move. I have not made any changes to the program in months, yet suddenly nothing in the UI tree works. Actually if I run the program over and over, every once in a while a button will work once, or a drag with start then freeze. The only thing I did recently we upgrade from 5.1 to 5.2. The UI was build in 5.1. I updated to 5.2.2p3 today but still no change. I feel I must be missing some setting change that occurred with 5.2.2 and no errors of any kind are showing up in the program at run time.