1: Your file appears to be corrupt. Please double-check that you have a working file on your computer by trying to open the rar/zip/7z file, and once it's uploaded to MTS, try to download the file and open it yourself to ensure that it got uploaded properly.
1: You have packed your creation into a rar, zip, or 7z file. However, you have double-compressed your file (a zip inside a zip, for example), which is not necessary and does not increase compression. Please put your files just inside a rar, zip, or 7z file without "nesting" them. You can use folders inside the file to organize things if you need to.
3: Your upload is properly packed into a rar, zip, or 7z file. However, you have included some additional stuff in your file (like a Thumbs.db file, images, text file, etc.) which are not necessary. Consider removing these from your file, as they are not needed for your creation to work.
5: Your upload is properly packed into a rar, zip, or 7z file, and you have not included any additional files or double-compressed anything.