Opening 8.5 files in X1 - This can't be right

I, too, have had some inconsistencies with X1 when opening older projects, created in previous versions. Not just instrument reroutes, but also more mysterious crashes, blanked out panels, etc. Which is a bummer, because this did not used to be an issue for me (meaning I could open, say, a sonar 6 project in sonar 8, no problem). I had grown to trust that older projects would move to new versions with me, but that didn't happen with X1, in my experience. My solution has been to finish any Sonar 8 projects in, wait for it, Sonar 8. Which is a bummer (I know, my second one in this paragraph), because I am working hard to get used to X1 and switching back and forth between versions is, well, a bummer. 

On the plus side, I look at this migration instability issue as one of those limitations that forces me to actually _finish_ some projects--meaning, get them to a point where they are okay (in Sonar 8/8.5) and call it quits, then move on to new projects in X1. (This might sound flippant, but I've really been approaching the situation you bring up this way.)

More to the point of your post: a workaround you might try to get an 8.x project into X1, though, is to load the project in 8, split ALL the simple instrument tracks (so you have a bunch of synth tracks and midi tracks), save it, and try loading that into X1. I think it's those simple instrument tracks that get screwy in the move to X1. (They're handy as heck, I use 'em all the time, but Sonar [all versions including X1] is still a little uncomfortable with them. They have the feel of a tacked-on feature, as opposed to truly integrated.)