[WIN10] Can't open multiple applications at once

A few months ago, I decided to move my toolbox and JetBrains app installations from my boot device to a secondary hard drive.  However, I may have botched something during the move, because now I observe the following oddities:

1) I cannot launch both PyCharm and CLion at the same time.  If, say, I have PyCharm open and I try to launch CLion, the launch fails.  No error message, no visible window.

2) When I close PyCharm and launch CLion, CLion opens the last project I was working on in PyCharm, and vice versa.  It's as though the two applications are sharing a state, even though their config directories are set to be different folders that are not symlinked to each other.

CLion settings directory:

PyCharm settings directory:

What did I mess up, and how do I fix this behavior?