My first question would be how does it fail? Is there an error message, does the page simple refresh, etc.? My first guess, though, is that sometime between clicking the Reply link and clicking the Submit post button the thread was either locked or the post deleted. Try going back to the thread you were attempting to reply to (do not use the back button...return to the forum and click on the thread) and see if any changes have occured. If that's the case, it's a current bug where you are not notified that the thread/post has been locked or deleted while you were typing a reply, so instead the page simply refreshes.
Let us know.
John
Why when trying to reply to posts do they fail when clicking the submit post tile?

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