Perhaps it's just me and my lack of knowing where the toggles are, but is there a toggle for the script editor in the toolset in which text you are writing does not overwrite what is already there? I just noticed this with the last update as well. It's akin to having the "Insert" key on for anyone who still remembers that old keyboard feature.
Anyway, it's rather a pain in the arse when making simple script edits inside the script editor and then realize you destroyed the entire code. Even hitting the space bar no longer makes a space, it voids what's in front of it. Any edit will write over/delete the character in front of where you typed. Is there a way to shut that off and go back to the way it was, or is this another toolset bug?