​@chhavisharma811 Please contact your Centre of Excellence group (admins) to verify your permissions are correct. They likely are, but this is a first step. 

Is your control room on-prem or in the cloud? If it is on-prem, have your CoE check the logs on the server. It should be clear what is wrong. If it is a cloud control room, please contact support for assistance.

It's a on prem server and we checked the logs, but nothing seems to be clear there. Though I have one doubt, is it possible that due to CPU usage, can this issue come? Cuz the CPU always spiking up from 80 to 100 on this CR’s DB server but then the whole CR is working, only this “scheduled activity” page is not loading.