It looks to me like your extension numbers changed, but the recording software is still configure as per previous extension range. The extension being recorded and the AMTClient's configured extension must match, else it will not popup.
To change the extension numbers refer to "Enable VOIP extension to be recorded" section in forum post:
How do I add a VOIP extension for recording? Instead of adding extension numbers, you will be changing the existing ones. Check that the rest of the configuration still applies.
PLEASE NOTE: Version numbers of software and warning message to ensure recordings will not be lost due to maintenance for extension range change.