This article is intended to describe scenarios that may trigger certain REST API error codes that may fall a bit outside the scope of what's implied or described by the error code given when executing a problematic call, or generally provide further details for when the error code reason is a bit vague.
Description: Generally, this means that "the request could not be understood by the server due to incorrect syntax."
However, we've identified an additional scenario where this is not the case. There are some hidden headers enabled by Default in Postman. Two of these have been identified as being needed to remain enabled, otherwise this error code will be returned, and those Header values are "Host" and "Content-Length".
In fact, if you hover over the "Host" value, you'll see it indicates a 400 error code will be possible without this Header enabled:
Description: An internal server error occurred.
Oftentimes, this error is triggered when a bad value is being passed. For example, your username isn't found in the system or is typed incorrectly; your password is 'test2', but you input 'test1', and so on, but there's another scenario surrounding this that occurs when attempting to login without specifying a password (i.e., you have "noPassword" set to 'true' in your REST API call). This will require the SIMPLE_AUTHENTICATION config record being added to your config db with the value set to "TRUE". You can read more about this in our Single-Sign-On Wiki entry here. The related details here are found under the LOGINUSERNOPASSWORD option under the Single Sign-On Functions header. Much like other YF Config DB changes, YF must be restarted after the change is applied.
The official RESTFUL API documentation for error codes also contains alternate wording from what is returned by Yellowfin and may be of assistance in troubleshooting specific error codes. This documentation can be referenced here.