Marxally
Exporting as HTML and using Winrar is not, and has never been, the correct method for uploading to the Arcade.
You must be using the latest version of C2 - r208 - and use the 'Export to Scirra Arcade' option. This will export the appropriate .zip file for you to upload.
Holy shit, I forgot that the zip file is in the generated folder, I am so fucking stupid xD
Thanks mate