NAV 2013 R2 Web service - HTTP 500 error when access codeunit objects via web service

Hi All,

I’d tried to execute codeunit function via Web service, However I always a HTTP 500 error when I test the URL from website.

I tried both standard codeunit and customized codeunit, and I got same error about HTTP 500 error. I also tried page function they work perfect.

Did I did something wrong? Does anyone got this problem before?

Thanks a lot