Cannot switch between text and visual on WordPress.

I have looked through all of the past comments on this matter and I haven’t found anything to help me.

I cannot switch between “visual” and “text” on editor while I’m trying to update my website. This has been an annoying minor problem for awhile now, but as of today I cannot switch at all… period. I’m stuck on visual, therefore I cannot type anything at all.

I just updated to version 4.2 on WordPress.
I have cleared my browser cache (I use Chrome).
I have tried to run this through Internet Explorer (it didn’t work).
I have deactivated plugins to see if that’s the conflict (it isn’t).
I have changed my theme to see if that’s the problem (it isn’t).

What do I do? I’m getting very frustrated because I just want to be able to post on my blog without all of this drama.