Stencyl 2.2 - (Released June 22nd)

Hm, yes, that looks stange, but I think the 'override' should not be removed actually. You just need to add the list:Array attribute (without the attribute it's a different function so you're not overriding anything, but with the attribute you are overriding the function in the parent class.)

OK I still had to remove the override, but found out that the file was being mixed up on the disk; I had two JSON.as files, one with the additional 'noise' in the name, and the project was confusing the two. I'd edit the one visible to edit, but the other file was what was being referenced. Removing the file from the project totally then creating a new code file and cutting and pasting the code in worked. However, I did still have to remove the override for update, draw and handleCollision.