Releasing the license and Re-activating the license

Hi,

 

Can anyone explain me what is the difference between releasing the license and re-activating the license on F5 units? To explain the scenario, we did try to upgrade the HA pair from 13.0 HF2 to 13.1.0 version but while re-activating the licenses, it did not change the service check date and we failed to upgrade the devices to 13.1 and we ended up upgrading the units to its hot fix version. For us, to upgrade the devices to 13.1 we need the service check date to be later than the License check date, in this case Sep. 12, 2017. Please provide the input as to what should be our next move and what is the difference between the above mentioned terms.

 

Thanks.