Hi,
Have you checked all the possible errors stated as in your error?
1. Do you have proper auth to create, proper system assigned with the dev role and ibase created?
2. is it new CR or you are trying to extend the scope? if this case, what is the status of CR? check out
ChaRM: RfC process stuck at "Being Implemented"
3. whether your project has the valid maintenance cycle assigned? you can check in solar_project_admin maintenance cycle is open ?
4. what is the phase status of maintenance cycle and project cycle. check this allows to create CD, with the status as development with release ?
Phases in the Project and Maintenance Cycle - SAP Documentation
please check
Thanks
Jansi