I'm trying using Fixer and am quite excited

I'm trying using Fixer and am quite excited by the possibilities but tbh a lot is going wrong.

For example, when I edit text - Double click and edit - The text changes colour (Becomes invisible) When I click out

Also I can't edit my front page. When I click on Upfront I get thanks for waiting and then a white screen with just the drop and drag elements on the left.

This is with Theme Tester, but i've done a brief test on a fresh site with just Fixer activated.