Issue
You are trying to add a domain on Acquia Cloud and get an error like - "An unknown error occurred. Please try your request again. If the problem persists, Contact Acquia Support. Request Id: xxxx"
Cause
This can occur if you have another Acquia Cloud application where the domain has already been added.
Resolution
- You will need to remove the domain associated with the other application before adding it to the new application on Acquia Cloud.