Hello folks,
Just to give some heads-up about it, it really seems an issue with the Extension’s Warehouse. I also got the same issue on Error code 500 while sending a new extension to the warehouse - #4 by DanRathbun .
It seems like by some (obviously unknown) reason, CloudFront is currently denying the extension upload. As CloudFront is used for CDN purposes, maybe its something related to some key that was rotated. Anyway, we need SketchUp team to check it, folks.
Thanks.