There's been an update to this tutorial following the renaming of the Arcade. You can find the new version 'Publishing to the Construct Arcade' here! An easy wa...
Yes, im having trouble even uploading my game as well. I have C3, and it's asking me to use c2 runtime. I know I can switch back but it's a lot of work that I have to do, such as take out things that C3 runtime uses that C2 runtime don't uses. C3 runtime runs very smoothly in my game and it's a shame it can't upload. However prayer sure do changes things and I know for sure someone is going to get down to the bottom of this so that C3 games can be add and it's runtime can be playable in the Scirra Arcade. I even made a post about this too in the "general discussion" forums.