Code is removed when switching between WYSIWYG/Code editor

What code are you talking about, specifically?

Formatting to text? like bold, italic, etc.

<iframes> and such, for 3rd party embeds things like youtube videos?

Or code in your blog posts, like examples of JS and PHP, etc?

I might as well answer all three:

If Formatting Text:

yes this is a problem, maybe a problem with a plugin, run basic troubleshooting (check Javascript Error Logs via your Web Inspector/ Firebug on Firefox), deactivate plugins and themes one-by-one until the error stops happening, then contact/research problematic plugin/theme.

If <iframes>

yes, this is annoying TinyMCE rips out most embeds and iframes and makes life difficult, if you’re wanting a third party code embedded, look into plugins or shortcodes for that specific third party service. (Jetpack.me also supports a ton of 3rd party embed codes if this is the case).

if code in your blog

This too is as annoying as the rest! I personally stopped using the “Visual” tab and wrote in a bunch of custom support for code, however, there’s tons of plugins that will allow you to use first and third party ways to embed code in your post without it getting mucked.

Example (a simple mouseover img hover effect pasted into Text View):
<a href="https://www.leadingpractice.com/certification/business-architect-expert/" title="Join our upcoming Business Architect eXpert certification event in New York"><img src="https://www.leadingpractice.com/wp-content/uploads/Upcoming-Certification-Business-Architect-eXpert.png" alt="Join our upcoming Business Architect eXpert certification event in New York" onmouseover="this.src='https://www.leadingpractice.com/wp-content/uploads/Upcoming-Certification-Business-Architect-eXpert-Hover.png'" onmouseout="this.src='https://www.leadingpractice.com/wp-content/uploads/Upcoming-Certification-Business-Architect-eXpert.png'" /></a>

Example (switching to Visual View then becomes):
<a title="Join our upcoming Business Architect eXpert certification event in New York" href="https://www.leadingpractice.com/certification/business-architect-expert/"><img src="https://www.leadingpractice.com/wp-content/uploads/Upcoming-Certification-Business-Architect-eXpert.png" alt="Join our upcoming Business Architect eXpert certification event in New York" /></a>

The result is that the mouseover hoover effect is killed because a piece of the code snippet is removed when switching views.

This also happens with our Paypal buy-buttons that contains a small bit of <form> code.

There are lots of other examples, this was just one typical example.

PS: I have both the “Black Studio TinyMCE Widget” and “TinyMCE Advanced” plugins installed on my website. But I do not think that they are the culprits – if I recall correctly I have previously tried to uninstall them, but to no avail.

Thank you!