Yeah, that was happening before today. Nitroflare was asking me for captchas even though I had a Premium Account. That seemed to go away (for now) while this "Cannot Check Account" error occurred afterwards.
I've been having some problems with Nitroflare and JDownloader lately.
I've also been having this other issue over here that nobody has responded to...
https://board.jdownloader.org/showth...415#post358415