The writer's had a perfect opportunity to tie up continuity issues ...

with the previous films but dropped the ball.


We all know that one of the biggest complaints with the Highlander franchise was the continuity between films was virtually nonexistent.

The writers of Endgame had the perfect opportunity to explain and reconcile continuity issues between films by having a sequence(complete to cuts from the other films) while Conner was locked away in The Sanctuary that said that he was locked away so long that he no longer was able to tell dream from reality- and Bam!

The events of films 2 and 3, and the end of the first could have been explained as the delusions and dreams of an immortal locked away and losing is sanity from the isolation.