Q: MainStage 3 - Not a reliable software for live performances

I recently spent a lot of money upgrading my Mac just to able to run backing tracks with MainStage 3, but even with the new improvements I've had no success. I have the latest version (MainStage 3.2.3) running on a mid 2010 Macbook Pro, 2.4 GHz Intel Core 2 Duo with 16 GB of RAM on a 240 SSD, OSX EL Capitan.

I have a clean desktop, basically a clean machine with everything stored on an external hard drive just to have the SSD handling the programs. When I perform I use the Perform window, I have Wi-Fi off, notifications off, but I keep getting that system overload message telling me that the audio engine was not able to process all required data in time.

I created my own custom template based on the 8 Backing Tracks default template. Some songs do take all the tracks, some don't but regardless of the template or what interface I use, I get the same results. I've also tried every possible variations under the program's setting with no luck.

Last Friday I spent quite a few hours setting up my session for Saturday's concert. The band practiced Sat morning and we went thought the set 3 times. At first, I was getting the system overload message frequently during practice but the sound was not skipping or stopping so I figured it was going to be ok as long as I didn't mess with the program at all.  MainsStage eventually closed abruptly so I had to restart. Few minutes later backing tracks just dropped, I was still getting the click and cues on my in-ear but everything that went to the house just died.

I tried removing and re-inserting the .caf steams on the affected tracks but they just wont play. Some songs didn't get affected, on others only a few tracks got affected.

You can see the screenshot above, the only track that plays properly is the first one even though all tracks have steams in them. The playback plugin is actually showing the audio for the 3rd track. So the plugin is loaded with audio but no waveform appear on the template for remaining tracks. It's very weird and very fu&%!! frustrating.

I noticed on the couple of times that we where able to go through the set that my CPU kept increasing as the set progressed. For example, while playing the first song the CPU was around 2 to 4%, song two increased it to 4 to 6%, and so on. By the time we where on the last song the CPU was around 25 spiking up to 35%.

I also noticed that some settings I do to the concert level wont stay saved, like setting the volume fader and meters to the metronome.

We ended up doing the gig without backing tracks. Very disappointed in this software. Very intuitive and the concept is perfect but man, it ***** that is not reliable for professional use. Unless someone here gives me an advise to get it to run flawlessly or point out something that I'm doing wrong I'm just going to have to ditch it and try something else. Maybe Ableton Live?

Any suggestions are welcome and very appreciated.

Thanks!