From the Model Mayhem FAQ:

What browsers work best with Model Mayhem?
The browsers that are best suited to run Model Mayhem are as follows:

  • Internet Explorer (most recent stable version)
  • Mozilla® Firefox® (most recent stable version)
  • Google Chrome™ (most recent stable version)
  • Apple® Safari® version 6 or higher on Mac OS X and iOS.

  • On January 12, 2016, Microsoft made an announcement about Internet Explorer Support.
    "Beginning January 12, 2016, only the most current version of Internet Explorer available for a supported operating system will receive technical supports and security updates. Internet Explorer 11 is the last version of Internet Explorer, and will continue to receive security updates, compatibility fixes, and technical support on Windows 7, Windows 8.1, and Windows 10.
    In response, Model Mayhem will also only be supporting IE 11, and will no longer investigate or correct issues relating to the use of any other IE browsers. If you are using these browsers and notice any features and functionality of Model Mayhem functioning improperly, please upgrade your browser or switch to a preferred alternative.

    We have also recently been made aware that Microsoft's Edge browsers experience some issues with Model Mayhem. We are working on increasing our compatibility with the Edge browser, but some Edge users may want to try changing browsers if a particular feature does not function.