This is a new one for me........for procedures or functions (procedures that return a value) I can't any parameters. Nor can I remove parameters from procedures already written.
If I create a new procedure you can hear the parameter "click" into place but then it just disappears and doesn't appear. Any idea what the heck is going on? Thanks!
What the heck.........logged out and logged into an incognito window. Now it works correctly AND (this is the fun part) it lost all my work for the last two hours. Cool.
Hello Angela
That should not be impossible - App Inventor is saving your Project very frequently. (Plus, you are saving backups to your PC regularly too......... 
)
I don't know if an incognito window is actually a good idea for working with App Inventor.
The symptoms of the issue you had might be broadband width related, but possibly they could be file corruption too. Before the issue started, what did you do?
I have encountered such a problem several times. Regarding these procedures and not saving blocks. Your internet had to disconnect and ai2 lost sessions. From now on, the procedures will have a problem with the inputs, and all the blocks you add will not be saved. Butl, ai2 does report that the session is lost in this way.
Hmmm very interesting...I might have had a screen saying it crashed then rebooted. Not fun. Thanks.