I feel like there is something in your settings that is causing this.
Can you zip them up and send them to me?
Instructions on how to do (as well as my email address) that can be found here: Minor GUI Issue with Beta - #12 by JohnDorlon
After you send them, you can probably solve it by resetting your options (you can then import your connections in again if you want). Instructions on how to do that are here: Toad for Oracle not working after in place upgrade to Win 10 - #2 by JohnDorlon (ignore the part about the Oracle client)