Cross-origin errors

[rmccue]

Errors aren't properly reported right now due to (apparently) cross-origin errors. We're setting the header though, so unsure what more is needed here.

[Shelob9]

I ran into this, I am assuming (untested) that it was because I am using fetch for requests and not allowing cross-origin requests.

[rmccue]

Did you manage to get a reproducible case? I’ve had trouble replicating it.