I have also just run into the same problem. I don't recall changing any settings in PDN, but everytime it tried to start up, it'd say there was an error. I go the choices to Debug or close, and I've kept hitting both, but both don't really fix it.
I uninstalled PDN, and when I tried to install it, I got to the part of installing it in which directory, hit "Next" it prompts me with the "Front end" problem.
It's annoying me because now I'll have to use Photoshop and I don't like it D:
Edit: I restarted my computer a few times. It warks again! >.<