Hello Harinath,
It seems there is an issue with RFC destination or the system alias which you have assigned while registering the service via /IWFND/MAINT_SERVICE.
Please go through the below link, which is similar to your issue.
SAP FIORI : LEAVE REQUEST ERROR in Launchpad.
Both Local Gateway and Local App should be checked No service found for namespace /SAP/ , ...
Regards,
Lokeswar.