Hi Teja. Thanks for the purchase, and sorry to hear you’re having issues. This particular problem hasn’t arisen but I’d be happy to try and help diagnose it. Are you trying to upload via FTP, or on the backend of your site? If FTP it wouldn’t have to be zipped up…but if you are going on the backend of the site and it’s generating that error, please make sure you’re running the latest version of WordPress and that you have no earlier versions of The Events Calendar/PRO active.
Make sure you also have proper permissions on your server to be doing this – from the looks of that message it seems the error may be server-side, but give those suggestions above a go first.