Refresh the page, if it doesn't work, open another browser (i.e., private mode or something).
I am in the same situation, where I accepted the HIT last week after the quota of participants was already used... I just attempted to both of your suggestions but neither worked. Even tried multiple browsers, but the exclusionary
Unfortunately, it appears that those of us who accepted the HIT last week but were not able participate are out of luck... Unless you are willing to revoke the exclusionary qualification for those of us who directly message you???