We use Datto RMM at work and when I go to launch the agent browser(The name of their tool) I get the above error. Most of the time I can close and open Firefox a few times and it will then work. Today however it will not work. I tried running FF in safe mode and still nothing. The setting under appilcations is correct and also the registry settings for the protocol cag are also correct. I can launch the software from IE which just makes me shutter.