Error message after searching for a CI

Hi Experts,
I need your help please.
SM 9.52 integrated with UCMDB

Whenever I search for a CI in SM, I get the following error message:

Error calling method: doSoapRequest in class: com/hp/ov/sm/server/utility/SoapClient Exception ( no protocol: null)

Can you please let me know what is it about & how can I fix it?