I've started using email Modules and ran into a possible issue.
I created a new email from the Snow Bunny template. The first time it opens, everything works and the Module tab appears normal.
But if I make any kind of edit, no matter how small, the Module tab breaks.
For example, if I click Edit Code and edit the HTML comment:
<!-- Marketo Variable Definition-->
I deleted the word Definition and then Saved.
The Module tab is now greyed out and unclickable.
It seems that just the act of saving breaks the Modules functionality.
Has anyone else encountered this?