After the change in the IP address of Cisco CallManager 4.x server, the Extended Services Application broke as a result. Now if the AppAdminis still configured to talk to Cisco CallManager at the old address, it cannot be authenticated because it needs to refer to the users created in AppAdmin, and the IP address cannot be updated. In a way it is broken because the address for Cisco CallManager needs to be updated, therefore it cannot updated.
In order to resolve this issue, locate ccndir.ini under C:\WINNT\system32\ccn on the server that runs the Extended Services. Open this file and change the Directory Server URL to the new IP Address. Save this file and restart Extended Services, and this should allow you to get back into the AppAdmin Page.
Then in order to get tool for auto-registered phones support (TAPS) to work, modify C:\taps\tapsccm.txt with new IP Address of Cisco CallManager.