I get the "The Pipes engine request failed (500)" problem when I try to run my pipe. Looks like a systemic problem and not something related directly to my pipe, but I'd love confirmation if anyone can help translate?
I'm getting that issue too..
It happened to one of my pipes, I cloned it and it worked fine...
Now I'm having this issue with a pipe that WAS working even earlier today...
Both your pipes seems to be working well.
In my case, I never got the 500 error unless there was something wrong either in my pipe or at the queried server (asking a wrong query for the most part).
If you have a pipe with recurring 500 error, could you post it here I can take a look?