Yes, this is a known issue due to incompatibility between discourse (discuss) and codechef username policies. Basically, underscores at the end of the username are not allowed in discourse. This requires a significant dev effort to fix, but we will get to it. Just that it’ll probably not happen for the next couple of months.
Can I do something else for it?? maybe changing the username or something like that?..If not can I get any tentative date…cuz it really creates some problem, people’s reply to our questions very much depend on our ratings