We have POST HTTP request which returns HTTP status code 400 (Bad request), so Neoload marks and considers the response as a failed one and gives error for it. In some special scenario we need to consider this response (even HTTP status=400) as successful. Is it possible make such a behavior?
NeoLoad will consider a response in error based on the HTTP status code. If the error already occurred during the record then you can configure NeoLoad to not consider it as an error.
It is done in the Preferences-->Project settings-->Runtime parameters.
However, if it did not happen during the record, it will be still marked as an error.
Also you can update the recorded response in the Design section and copy/paste the new recorded response to suit your needs. That way if that recorded response is an HTTP 400 error then the error will be ignored during runtime.
For more information, see "Runtime" under "Preferences" section in NeoLoad documentation.