Both submit buttons work here in 10.0.2. If you have javascript disabled, enable it. Or if you have noscript addon enabled, disable it. If none of that works then

Help => Restart with addons disabled and try it again. If it works then you have an addon(s) that are in conflict. Post back here with results.

Make sure that your text isn't too long if you can't submit your message.

not very helpful. what constitutes "too long"? I don't think mine was.

The maximum allowed characters is 250. If your message is 251 characters the green 250 changes to a red -1 and the submit button doesn't work. It was just a suggestion, we're here to help.