Hey @richamatta95,
Welcome to the community! 
You might need to provide more context here, that error alone won’t tell anyone anything. 
What’s the test checking for? Can you provide the script and the response it’s asserting against?
You could try adding some logging (console.log(pm.response.json())) to your collection and seeing this in the report with the --reporter-htmlextra-logs flag. Making sure you save the collection and update the file before running it through Newman again.
This test is basically to query the AWS dynamoDB .
Basically we are using a PUT API call of xyz service and querying AWS to compare the request
All the fields are set as the global variable in the PUT request
Logs
DynamoDb throws 400 bad request in Newman
whereas hitting the same URL in postman gives 200 ok response
Are you specifying that global variable file in the Newman command?
I tried with both specifying and not specifying but the error remains the same
What test is failing?
I can see a 400 code but what’s the actual test you’re running?
This test basically to query AWS dynamoDB
You’re talking about the request, a test script within the request would be failing and giving you that assertion message. 