Watchmaster... my inbox is full and I am trying to delete some messages as I have some on "hold" (because inbox is full). However, whenever I try to delete some messages I keep getting this message... "The submitted form was invalid. Try submitting again".
It probably has to do with stored cookies on your pc.
Try deleting the cookies from your browser and try again.
For Chrome:
On your computer, open Chrome.
At the top right, click More. Settings.
At the bottom, click Advanced.
Under "Privacy and security," click Site settings.
Click Cookies. See all cookies and site data.
At the top right, search for the website's name.
To the right of the site, click Remove .