Can't switch between visual and text

I would guess this is a theme issue, or a plugin issue. Have you tried switching to the default theme and turning off all plugins?

Yes and I’ve turned off enough. And if you do a google search I seem to not be the only one having this problem.

If the issue persists with all plugins deactivated and the Twenty Fifteen/ Fourteen theme active, then I recommend you use your browser to debug any JavaScript or other errors: https://codex.www.ads-software.com/Using_Your_Browser_to_Diagnose_JavaScript_Errors

Although it can look like you’re facing the same issue as someone else, it can just mean you have the same symptom. A solution for one person does not mean it will work for others.

Sorry for hassle….the problem is https://www.ads-software.com/plugins/dont-muck-my-markup/

Which wouldn’t be needed if the default editor knew how to leave our html alone. So yes….the upgrades to the editor in 4.3 broke MY standard installation because I always have to employ extra steps in the first place to make the editors behave properly.

Could you post a support topic here: https://www.ads-software.com/support/plugin/dont-muck-my-markup#postform – notifying the author of the issue