Overwolf bought / acquired the Twitch - CurseForge launcher and then failed to implement or protect existing software installs and configurations.
I had 8 working, actively used Minecraft modpacks that have been in use for several years, all working without issues. It appears that OverWolf is ignoring the fact that a few simple steps would allow the features provided previous to their acquisition to keep working by using a simple text file containing the minecraft version number and then provide a centralized repository for minecraft.jar and forgecraft.jar files for each required version. Clicking launch is just starting a Java Runtime Environment with some flags (that are already stored in the launcher), pointing it to the correct jar file, pack folders and then stepping out of the way.
Please do something soon, it has been almost 2 months!