Validation error accessing donation from module

There is a strange validation error when accessing the donation form through mod_jdonation. Just checked it on your demo to make sure it didn't have anything to do with my site configuration and your demo shows the same error. Although donation amount is chosen, validation error shows:

Thanks for reporting the issue. I am busy today, so I am going to review the code and correct it (if the error is valid) on tomorrow

Regards,

Tuan