There is a problem with the server Sorry, the server has encountered an error. It is either not available or it can't respond at this time. Please contact your system administrator 500 Error. SOAP Dynamics 35 F&O API

I was getting the below error while trying to access the newly created endpoint through SOAP.

All my services and service groups looks good. But. still I was getting this error. 

I did a small mistake but it took about  6 hours for me to identify the issue.

Reason: 

In the service class I used different parameter name and in the coding I used a different name. The names are not matching and SOAP service is throwing 500 error.

After changing the name the SOAP service worked.

Don't forget to build the solution.

If you still having the same problem, make sure your code is correct.

@Rahul