Crusade is a spin-off series from Babylon 5 which first aired in 1999. Before even one episode had aired, Crusade already had been cancelled. it never got a chance post the short first season of 13 episodes. Like Babylon 5, Crusade also had a five year story arc. Although the Drakh plague storyline would not have taken 5 years according to creator J.M.S. Straczynski which he mentions during the commentary on A Call to Arms. It would take about two seasons.

TNT no longer seemed interested because according to them, TNT audience were not interested in Crusade. J.M.S Straczynski believes that TNT wanted out of their contract because it would not have been the kind of TV shows they wanted. TNT figured out that people who watched Babylon 5, didn't watch any other scripted shows on TNT and vice versa. 

Then there also was the uniform problem (taken from Babylon5.fandom): On September 22, 1998 JMS revealed that production of Crusade would be put on a brief hiatus. This was to build new sets and to bring in newer uniforms. Production was due to start up again on October 19. During The Hiatus TNT decided that rather than Crusade's first season beginning months after the Drakh attack, the first episode should instead be a "coming together" episode (this would become War Zone). TNT wanted the new sets and costumes in place for all new episodes. The Black Uniforms as first seen in War Zone were TNT's new Uniforms however were the original uniforms in the chronology of the series. As such an episode was written where "new" uniforms would be introduced, these would in fact be the original "bellhop" uniforms, after this episode the five episodes that were originally produced would air. Then there was a planned episode in which there would be a "laundry accident" and the crew would switch back to the old uniforms (TNT's mandated new uniforms).

Sci-fi channel tried to obtain the series and hopefully continue with the airing the show but it was too expensive. Sci-fi channel already allocated the majority of their budget for 1999.

So a potentially great TV show was cancelled before it even began, which is a real shame because we need(ed) to see more of the very interesting and entertaining Babylon 5 Universe. 

Galen