When the workflow licence expires it effectively disables Nintex. This is very disruptive on either a production or even development environments that use the addin. Yes it is the client responsibility to remain licenced but in real life this is easily missed (in the absence of any reminder emails, system warning, or dedicated admin staff to keep an eye on this). I suggest on expiry Nintext enters a grace period where it still functions but displays ‘nag’ messages to remind people to register. This is common with trial software but I suggest to do this for the production licences. Better than bring someone’s core business processes to a halt.