Solution Manager - IDoc Monitoir no available

Hi SAP Solution Manager Experts

Please can i get assistance in understanding why i am having the following issue :

i am setting Business Processing Monitoring for IDOC monitoring .

I am trying to define a monitor for IDOC Monitoring but i  do not see it in the list of monitors

i did some investigations and in the Set Up Guide for Interface Monitoring they mention that i need to Update the Central Application
Repository .. so i follow the guide and for some reason i can find the same path as described in the document

your assistance is highly appreciated

Thank you

Ravi