Hi Farhaan,
do you have only one certificate or multiple certificate? HTTPS can have 2 or 3 certificates (Root, Intermediate [optional, if any 3rd party person is there in the middle then we can get this certificate] and system certificates).
The issue is with the certificate and it can be because All the certificate is not present or path is not correct.
Please refer the below wiki in which solution is given for this peroblem.
Troubleshooting 7.1 - End-User Experience Monitoring - SCN Wiki
The similar issue is resolved by applying SP level patch, please refer the below discussion
SAP PI 7. 3 HTTP_AAE Receiver with SSL
Please check the below blog -
Configure the HTTP_AAE receiver communication channel with SSL
please also check the below discussion
Where to Import Clients SSL certificate for HTTP_AAE
regards,
Harish