The license is not specifically stated, and so defaults to "All Rights Reserved". This means developers looking to fork this mod in the future if it's ever abandoned would be unable to do so. Addons would also fall under violation. One of your terms of use is no reuploads or hosted modifications of the mod, so this may pose a problem with a GPLv3-compatible license. I hope this can be resolved, as a mod I've come to love, BetterPortals, is unable to add support because this mod lacks a license.