There are just few revocations per license allowed. You have probably used your revocation limit on this license.
In order to pause license, you have to configured your ZModeler to manage license automatically.
1. In your account on "My computers" page your platform should have "Allow this platform to login" option toggled; platform should have a password assigned too (say, 123456)
2. In ZModeler on Account Setup page you should specify you account username and platform password (123456).
3. Once you revoke your license in account, your license will have an exclamation icon on it.
4. Start Zmodeler and open License information page. If you have properly configured in step 1 and 2, ZModeler will void your license (license will disappear from ZModeler). Then you can check in account to ensure no more "exclamation" icon is shown on your license.
Note, when license was revoked and ZModeler did not confirmed license revocation, you see an exclamation icon on license and license time is still elapsing. Once ZModeler confirms license revocation, license is paused.