Let me just start off and say that I love the idea of this program. I think that, in concept, it is terrific! An easy to use MIDI program that comes with a bunch of plugins, straight out of the gate? Sounds pretty good. 
Anyway, I've been using LMMS for several months now, and have tried both the most recent "stable" version, as well as the beta, and both have caused me several issues.
1. When loading up a free VST I have called Proteus VX, LMMS will almost always crash. I have gotten around this somehow a couple of times, but it's always extremely awkward, and requires moving the VST, and reloading it when the project is finished starting up.
2. Random glitches when deleting sections of MIDI data. I've noticed these happen most frequently when I use my EZDrummer 2 VST. If I delete a section of track, it sometimes causes the program to crash. If by some miracle that doesn't happen, but I decide that I want to bring a section back, I click undo, and it unloads the VST.
3. Finally, and most importantly, sometimes I load up a project, and sections of the MIDI are gone. I've tried reloading the program, but it doesn't do anything. Pieces of my work have disappeared into thin air, and I've made a habit of exporting the project in both MIDI (which actually ended up being useless, as I can't actually import it back in properly), and WAV formats, to back things up.
Anyway, I've been using LMMS for several months now, and have tried both the most recent "stable" version, as well as the beta, and both have caused me several issues.
1. When loading up a free VST I have called Proteus VX, LMMS will almost always crash. I have gotten around this somehow a couple of times, but it's always extremely awkward, and requires moving the VST, and reloading it when the project is finished starting up.
2. Random glitches when deleting sections of MIDI data. I've noticed these happen most frequently when I use my EZDrummer 2 VST. If I delete a section of track, it sometimes causes the program to crash. If by some miracle that doesn't happen, but I decide that I want to bring a section back, I click undo, and it unloads the VST.
3. Finally, and most importantly, sometimes I load up a project, and sections of the MIDI are gone. I've tried reloading the program, but it doesn't do anything. Pieces of my work have disappeared into thin air, and I've made a habit of exporting the project in both MIDI (which actually ended up being useless, as I can't actually import it back in properly), and WAV formats, to back things up.