Same issue with a 18 Nav L Black Label, connected to wifi automatic updates fails every single time, last update was build date of 12/17. I was able to update SYNC via USB 2 weeks ago and yesterday I downloaded a rather large complimentary map update from Lincoln map update website that took 30 min to download and 60 min to install into truck all via USB flash drive. Adding to the comments above there absolutely have been updates to both SYNC and Maps however something is wrong with either the onboard modem or APIM in the vehicle, even after both USB updates I tried again to scan for automatic updates and it failed with the same message of try again later when convenient. Appointment to drop off at dealer this morning for the dreaded oil pan leak and VCT solenoid failure, will have them look into the update issue and report back as to what they find.