Is anyone using

https.requestRestlet

to successfully make a POST call? I am able to do a GET successfully from a Suitelet to a RESTlet but POST is returning a 500 response with a "contact support" error no matter what I do.

In some scenarios involving RESTlets, you need to set the header:

"Accept: application/json

I can't remember exactly from the top of my head but try that.

That was a good thought. I added a

content-type

header and now get a 400 syntax error code. That's progress at least.