This message is only received when the engine is unable to pick up your check because an issue with the settings.
There are a couple reasons this error could be sent:
You have selected the incorrect programming language. Check to make sure that you have used the correct programming language. If you need to change the settings of the check click the tab underlined below:
2. You have not correctly zipped your files, if you believe you are using the correct language attempt to re zip files and resubmit to checker.