MIDI suddenly stops

As the title says, I'll have a song with MIDI drums and keys (for example), that are prerecorded. During playback, one of the MIDI tracks will suddenly stop. Some times it's the whole track, sometimes it's just one of the notes. So, on a drum track for example, the kick will suddenly stop working or on the keys, one of the notes that's being played will just stop being there. Other times, the whole track will suddenly drop out. The only thing that makes it come back is to shut down and reopen Reaper. When it stops, it stops suddenly. It will be working and then just suddenly stop working. It never seems to be in the same place twice so I know it's not a certain sound or group of sounds that's causing it. This is completely random and will even do it during rendering. Has anyone seen this before? I have no idea where to start? For the record, I'm using the Reaper demo though Windows 8.1 and have a MOTU Ultralite for my audio.

I was able to figure out what was happening. Just in case it's happening to anyone else, I had a delay plug in effect, along with the VSTi drums. For what ever reason, the delay was causing the drums to intermittently drop out. I moved the delay to it's own channel and used the drum track's "Send" to add the effect back in. Worked like a charm and no more drop out!

Which delay effect? Would be helpful to know for all of us.

Sorry.. It was a VST called "EpicVerb". However, I had the same issue with several other effects.

Hi all, I had this problem, midi notes would cut off when playing, or rendering. It was resolved by upgrading my hdd to an ssd. I had a slow hard drive that couldnt access the samples quickly enough, (I dont know if they were being storred in the page file, that could explain it) but the hard drive couldnt keep up and the samples just cut off. I would suggest investing in a faster hard drive, or an ssd. I did, and its the best investment I ever made :-)