Logic X hangs when moving arrangement markers
I'm using arrangement markers to organize a song (first time doing that). I set the arrangement markers to fit the different pieces (Intro, bridge, chorus, verse, etc.), and then set track markers to correspond to the start and end of each arrangement marker. I had been able to grab the arrangement markers, and able to move/drag, for instance, the position of the chorus to a new position in the song.
But I am now experiencing fatal hangs (beachballs) when I try to move arrangement markers. I have Googled this one a bit, and cannot seem to find a similar issue elsewhere. What am I doing wrong here? I'm on 10.1.1.
MacBook Pro with Retina display, OS X Yosemite (10.10.4)