Recently I installed Visual Studio 2017 Enterprise and when I open any file (like .cs,.cshtml), every time the cursor changes to a gray rectangle and the editor acts as if its in Over-strike mode even though the indicator at the bottom of the window says "INS".
So I hit the Insert button several times and cycle through "OVR" and back to "INS" and the cursor goes back to "|" and I start to coding. Then the moment I highlight some text it happens all over again. This is very frustrating and also painful.
Double clicking the indicator has the same temporary result as the Insert button.
So how can I solve my problem permanently?
I also faced a similar type of problem. I had VsVim extension installed in my VS. After uninstalling the VsVim extension, my problem was resolved. Do you have VsVim installed? if so, you can give it a try. If that doesn't solve the problem, try to uninstall the extensions you have in your VS and check if any of them is causing this trouble. (I am really not sure why VsVim was giving me this sort of trouble). Hope this helps. Ciao! :)