Can't edit 'footer' templates in custom styles
 

I have three styles - the Default Style* another style that's a child of the Default* and a third style which is a child of the second style.

In the two custom styles* I'm not able to edit the 'footer' template. I tried editing a few other templates and had no problems* it was just the footer template. After editing* once I hit Save or Save & Reload* I get redirected to a blank frame (an image of that) and the changes are not saved.

What could be causing this issue? I have 3.6.8. I recently transferred the forum to a new server; don't know if that's somehow related to this.