Getting error 500 in response code in jmeter

I have recorded a login transaction using Firefox. Now when i run via Jmeter I get Response code:500 and Response message:Internal Server Error. The same works fine when run manually.

I have done the correlation. Dunno where and what to check more?

Attaching the screen shot of the error. enter image description 开发者_JAVA百科hereenter image description hereenter image description hereenter image description here

As per 500 Internal Server Error description:

The HyperText Transfer Protocol (HTTP) 500 Internal Server Error server error response code indicates that the server encountered an unexpected condition that prevented it from fulfilling the request.

This error response is a generic "catch-all" response. Usually, this indicates the server cannot find a better 5xx error code to response. Sometimes, server administrators log error responses like the 500 status code with more details about the request to prevent the error from happening again in the future.

So if you want the reason - you need to check your server logs.

Additionally you might want to check whether your correlation really works, i.e. double check JMeter Variables originating from correlation using Debug Sampler and ensure that they're extracted fully and correctly. In certain cases you need to perform encoding or decoding of the extracted variable