I have this issue as well. I've tried this solution:
Problem: Unable to change mods Using the Mod Select function.
Reason: Likely you don't have .cfg files set to be read yet.
Solution: go to AppData\Roaming\.techniclauncher\technicssp\config and right click on any of the .cfg files there. click open with and set it to always run with notepad.(Macs use textedit) Now you can change mods within the launcher.
If the option is greyed out just click on the big technic logo and it should become active again.
But it hasn't helped me. When I click the "ModSelect" button, it opens up a window which has all my desktop icons in it. It's quite bothersome, seeing as I don't want certain mods.
Windows user, btw.
Thing is, I have the same issue if I open up regular minecraft, click "Open texture pack folder" and I get the same window with my desktop stuff in -.-''
