I’ve posted several comments to Q1193 on the L3P before, and never hit an error. When I posted comment 40302, I received this error:
I hit the browser back button and resubmitted the comment and it submitted just fine.
This relatively rare error occurs when you use a stale form, usually by loading the form, then logging in in a different tab before submitting the form. (Another possibility is that you happened to be working on the comment around the same time as a software update, not sure about that though.) Reloading and resubmitting will always work, and as this is a security measure, there’s nothing to be changed here.