In the hope this may help someone, we had our first experience of v17 server license expire on a LAN based system where we provide on-demand support but are not directly responsible for the systems there.
This is our first (only) customer where we have installed FMS v17 and ironically their license agreement was due to expire not too long after setup.
The installation went along the normal lines where the MD of the company is the registered contact for FileMaker and he couldn't find any of the maintenance release emails (he has 7 separate email addresses and they'd also gone through a domain name change), hence we had to contact our UK FileMaker team to send us a copy of the maintenance email so we could download and install the license file (delayed start).
In mid October we were contacted on a Friday (just as we were leaving for a meeting) to inform us that their whole FileMaker system had gone offline Thursday lunchtime! Their 3rd party support IT team were contacted initially and they'd finally found a reference to a FileMaker Server licensing issue within the (Windows) server event viewer.
It transpired the license expired in mid-September, which was displayed within the admin console, FileMaker Server had provided them with a month's grace period and then refused any connections after that.
They are on an AVLA and had recently renewed for 2-years (our expectations had been that once they renewed their AVLA the server license would automatically update.), so we again started the process of trying to find the renewal email, which again couldn't be found. This time we were under pressure due to the company having come to halt as far as data processing (and invoicing) was concerned and we were failing miserably trying to obtain a renewal email.
Partly in desperation, I downloaded the original license file from the (now expired) maintenance email and uploaded this again within the admin console, at which point the the expiry date jumped 2-years forward in time to mid-September 2020.
As this is our first experience of v17 licensing expiring and our first experience of FileMaker Server bringing a company to a standstill due to licensing, we are not sure whether this is now to be the normal behaviour?
Until we have more experience, or those who know can clarify whether this is the expected behaviour, we recommend keeping a diary note of those expiry dates displayed in the FMS v17 Dashboard.