This is happening with the 13.2.0.113 version and I have recreated in the 13.1.0.78 version.
The last file I had opened was on a network share. I clicked on the Open File button to open a different script. On the Open screen, I clicked on the Up One Level button to the top level of the share that I have access to, then I clicked it once more accidentally and Toad just crashes with no error message.