After all, thanks for the support by x-aviation's team. After many tests, I can confirm 2 things for all mac users : - No crash anymore after removing Xpushback (don't make confusion with SimplePushback) and Airport navigator. - I'm running an i5 (27'' screen), with only a 512 Ko video card. With the texture settings on "extreme", x-plane crashes when approaching airports with many objects (like LFPO, Orly in Paris). But with the settings on "high resolution", this is OK. No problem with the fonts (at least, I hope so, in french we have an expression saying "I cross the fingers"...) The CRJ is now my favorite plane to fly online. XP has now an excellent liner to fly with. Thank's Javier. And with the next update of Tom's MU2, my air company will definitely be x-aviation !! Daniel.