Hi.  It looks like we introduced a small bug into Leash last April 
which caused this build failure.  (We only create a new Windows release 
every few years, and our continuous integration for Windows doesn't 
currently include the Leash build.)

You should be able to rectify this bug by editing 
src/windows/leash/LeashView.h, searching for AddDisplayItem, and 
changing the three "long" parameters (issued, valid_until, and 
renew_until) to "time_t".  Let me know if that works.