Problem scenario
You added an A Record to DNS in Active Directory. You accidentally added the FQDN and the parent domain name was added. Now the A Record is too long and has a duplicative domain name like this:
server1.continualintegration.com.continualintegration.com
You tried modifying the FQDN in the A record, but it was immutable. What should you do?
Solution
Try waiting one hour. This problem may correct itself. It is possible that A.D. will notice it and fix it.