Workflow Rest API Block Error (Invalid Json)

Hi!

I have a workflow that is used to generate shipping labels for USPS. Yesterday, we ran into a very obscure issue where the API end-point was giving an Invalid JSON request response.

The workflow had been running on schedule for days and we did not face any issue. Morning of 20th November, we ran into this issue and it persisted the entire day.

The External API End-point (USPS) was working fine, I tested identical objects on Postman and through the Workflow REST API Block. The workfow always gave the error.

The solution was deleting and adding a fresh Rest API Block. I replicated the same logic and it worked!

Some guidance from developers would be appreciated as to why such issues occur and how to debug them.