Error -26612: HTTP Status-Code=500 (Internal Server Error)

Hi,

Newbie to Loadrunner. Trying to generate a simple script and make it run for 3 users is failing. :(

Issue 1:

    lr_save_string("\"RegistrationId\":2,\"DefectTypeId\":1,\"BaseId\":1,\"ATAId\":275,\"Description\":\"Defect3\",\"TaskText\":\"Defect3\",\"DefectStatusId\":1" , "Body" );
    

    web_custom_request("SaveDefect", 
        "URL=http://localhost/Envision.Web/Components/Defect/SaveDefect", 
        "Method=POST", 
        "Resource=0", 
        "RecContentType=application/json", 
        "Referer=http://localhost/Envision.Web/Home/Index", 
        "Snapshot=t73.inf", 
        "Mode=HTTP", 
        "EncType=application/json", 
        "Body={Body}", 
        LAST);

when exectuted this is trowing this error

Error 658 Action.c(658): Error -26612: HTTP Status-Code=500 (Internal Server Error) for "http://localhost/Envision.Web/Components/Defect/SaveDefect"   [MsgId: MERR-26612] Action.c C:\Users\Rafiq.Mohammed\Documents\VuGen\Scripts\Defects Defects

Issue 2

Earlier in Body it tried include Parameter Description by creating a parameter called Desc and adding two values to it and in the Body tag replace "Defect3\" with {Desc} and changing the run iteration to 2 and ran still I got the same -26612: HTTP Status-Code=500 error

"\"RegistrationId\":2,\"DefectTypeId\":1,\"BaseId\":1,\"ATAId\":275,\"Description\":\"Defect3\",\"TaskText\":\"Defect3\",\"DefectStatusId\":1"

This is my first script so in big confusion

Thanks.