Only allow submission of an invite form if the custom text length is acceptable
Regarding the new 254 character limit on custom messages in collaborator invites:
If there is an invalid email address in the top field, it is highlighted with a red message and the invite cannot be sent until the exception is fixed.
If there is an invalid message length in the bottom field, then it should be highlighted in red and the invite cannot be sent until the exception is fixed.
Or, just prevent that field from containing more than 254 characters. Some sites include a "remaining characters" counter next to the window to make this limitation clear.
The current user experience of allowing the form to be submitted and then responding with a failure banner is bad. I had a user today who thought she had invited people to a folder when she hadn't -- she had submitted the invite with a too-long custom message, switched tabs, and never saw the failure banner. She has reinvited them and followed up with an email containing the 350-character communication she needed them to receive about it.
