Overwolf is based on .NET 4.5. It's possible that .NET 4.5 wasn't installed properly on your PC.
In this case Overwolf won't be able to run due to some corrupted files.

This scenario might occur due to a Windows update gone wrong, like updating it from Windows 7/8/8.1 to Windows 10, or even due to outdated drivers.
We found that the best solution as for now is reinstalling your .NET 4.5, this is how you do it:

  1. Press the Windows key + R
  2. Type in: appwiz.cpl
  3. Click on "Turn Windows features on or off"
  4. Look for the ".NET Framework 4.5/4.6" and uncheck it
  5. Click "OK" and wait
  6. Once it is done close it and restart your computer
  7. Follow steps 1-4 in order to re-check the ".NET Framework 4.5/4.6/4.8" option
  8. Restart your computer
  9. Try running Overwolf