I thought I should mention something I noticed a few days ago. I noticed this just after purchasing a new computer but don't think that should be the reason for the difference as I was running Windows 8.1 and IE 11 on the old as well as new computer.

In my old computer I had Tribalpages in compatibility view. I had no problems editing anywhere in the site.

I had forgotten about compatibility view when using the new computer and editing went well until I tried to change something in the about section on the home page. I found I could delete words and letters but not replace anything. Everywhere else I checked in the computer editing worked fine. I could even change the banner on the home page successfully, but not wording in the "about" section.

Fortunately I remembered compatibility view and sure enough, in that mode, I could successfully carry out editing in the "about" section on the home page.

I mention this in case someone experiences the same problem.