Sagemaker Canvas 502 Bad Gateway Error

Did you ever figure this out? Running into the same issue. I was not running into this issue on an earlier domain which I had built using the quick setup option.

From what I remember I had created the Sagemaker domain with the incorrect permissions setup. I deleted the domain, started again, made sure to give more access, and that solved it - sorry I can't be more specific, it was a while ago! But that's probably the problem if you used the quick setup.