exams2blackboard

Dear community, when I generate the file "blackboard.zip", with the command "exams2blackboard(myexam, n=10, encoding = "utf8", eval = list(partial = T, negative = T, rule = "false"))" and then upload it to the "Blackboard" platform an error occurs: "The provided .zip file could not be imported".

Could someone tell me how to fix it?

Thanks
Best regards