X was charged with failing to file the annual report required of sex offenders under AS 11.56.840(a). This statute requires proof that the defendant "knowingly failed" to file the required report. X (who represented himself in the district court) asserted that he was innocent because he had not "knowingly" failed to file the report. He claimed that he had merely forgotten to file it. The prosecutor suggested that X enter a Cooksey plea to the charge. X accepted this offer. He pleaded no contest with the understanding that he would be allowed to litigate his claim that he had not acted "knowingly" because he had merely acted forgetfully. On appeal, the State correctly points out that this issue is not appropriate for resolution in a Cooksey plea. Obviously, if the State were unable to prove that X acted with the required culpable mental state ("knowingly"), then this failure of proof would be dispositive of the charge against X. But X's mental state is a question of fact. the State has not conceded that X is factually innocent of the charge. That being so, it is impossible to determine whether X acted "knowingly" without holding a trial. Because there has been no trial, it is impossible for us (or any appellate court) to resolve the claim that X attempted to preserve when he entered his Cooksey plea. We therefore agree with the State that this was not a proper Cooksey plea. X was promised that, if he pleaded no contest, he would be able to litigate the issue of whether he acted "knowingly" when he failed to file the report. Because we conclude that this is not a proper issue for a Cooksey plea, X has not received the anticipated benefit of this bargain. For this reason, X must be given the opportunity to withdraw his plea and go to trial. This appeal is DISMISSED. We remand X's case to the district court, where X must be given the chance to withdraw his no contest plea.