421 idle timeout ?

Hope this is the right place to post.If you are using AVIRA you may not be able to submit files to check for safety.Turn off AVIRA guard,should fix.It worked for me.
pregister (:KWL)

Thats only if your using clean pc mode. I have D+ set to safe mode cause I do not feel the need to have pending files. Submitting files and having errors has been a problem for while now and its not related to Avira cause when I was using NOD32 submitting files worked and didn’t work. Its a server problem on Comodo’s end. Sometimes it takes 2-3 times to submit files but eventually they go in.