You probably need a couple of things
1) Less Turkish issues
2) More stable Christendom.
3) More stable Roman Empire
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1) Less issues with the turks provides fewer justifications for Crusade
2) More stable Christendom means the Pope doesn't seek a way to stop the fighting
3) More stable Roman Empire means that Alexios doesn't ask for help.
Fail to account for any of these factors, and something is still going to happen.
For example, if 3 stops being an issue, the Pope will encourage Crusader action in Spain - which was already a thing - they still need the help. In fact, he had to actively prevent the Spanish from joining the Crusades. I actually think that this would be more successful, with the Crusaders taking over Spain, and maybe even Africa - without the problem of extant Muslim powers wanting to re-invade.
Miss out 2 and a similar scenario may take place.
Miss out 1 and the Pope may well endorse Alexios' request, rather than make it about the Holy Land.
Now, I'll include the caveat of individual actors and persuasion, but those are the three big acts to cause the Crusade.