Your agent registers as offline and the following error appears in the Core AppRecovery.log, for example:

ERROR 2015-01-05T17:06:25 [1000] - Replay.Core.Implementation.Agents.ProtectedAgent () Verification ids is failed: Core agent id 64e232ae-375d-40e3-8948-4860838d2336, agent id 251ba194-1145-407d-b8f8-08a75c1cf2c4

Quest does not provide support for problems that arise from improper modification of the registry. The Windows registry contains information critical to your computer and applications. Make sure you back up the registry before modifying it. For more information on the Windows Registry Editor and how to back up and restore it, refer to Microsoft Article ID 256986 “Description of the Microsoft Windows registry” at Microsoft Support.

On the Core select the Agent.The Agent ID will be found in the Web URL, for example, https://Agent1:8006/apprecovery/admin/ProtectedMachine/64e232ae-375d-40e3-8948-4860838d2336/Details. In this case the Agent ID is 64e232ae-375d-40e3-8948-4860838d2336.

1. You can also find the Agent ID in the registry of the Core. Open the registry and go to HKLM\SOFTWARE\AppRecovery\Core\Agents. You will see the Agents listed by Agent ID. Find the ID in question, select it, and the Display Name of the agent will be shown to verify against.
2. Go to the Agent having the issue and stop the Agent Service.
3. Open the Agent registry and go to HKLM\SOFTWARE\AppRecovery\Agent\AgentId\. Export AgentId to desktop as back up.
4. Double click DWORD Id and replace value with correct Agent ID value from core.
5. Start Agent Service, go to Core, and refresh metadata for Agent. Agent will be online.

For Linux agents, please refer to KB259849