I'm just testing out on my dev machine with Moodle 2.5 before I go into production and there's one last bug to squash. What's happening is this:
Any form (gotten by adding something to a course) that has as a required parameter as a textarea, (1) first loads up normally (2) but just at the end of the loading, it disappears.
I turned on complete dev log and there are no errors or messages given. I tried on different themes and got the same result.
We are seeing the same situation intermittently and not consistently. Most often, it is solved by refreshing the screen. Right this minute, I have instance where the refresh does not solve the problem.
Looking at the html in my current problem, it seems to be identical to html on this forum where the text area is visible. and, in fact as you can see, it calls the textarea.
I know this is a year later. We're using 2.6.1 and this happens in both Chrome and FF.