so I asked this a while back and got no answers. It wasn't my thread so I guess thats why.
When I open an existing midi track type 1 (multiple tracks) there are tracks missing. So I have to insert a midi track (anywhere I want) and then all the tracks show up. Could be a midi project I sequences myself, one I downloaded or or one I purchased when rushed. Does not matter.
Pretty annoying.I have NO default softsynth set. I did try that from a response in the orig thread. 
Makes no difference. This started with the most recent update to Splat. I am all about midi and pretty savvy about it 25+ years.
 
Any ideas? 

Anyone? Is this really something that has never been seen by mankind before? 

I mentioned I do own a reaper license...bought a while ago. Anyway, no problem with exact same midi files in reaper?
My default midi device is set to Echo Layla 3G as it has been for many years, 
 It is so bizarre that adding a midi track, any track # makes the other tracks appear.
 
Doesn't that catch anyone's inquiring mind? Huh?

I really don't know personally but have you tried opening them with TTS 1 ?
Sorry not my strong point using midi 1 files just wanted to bump your thread, help any way I could.
 
You also might be able to right click on the midi file and choose Open with: Sonar
 

It is strange and I've never heard of it happening before.
Is it possible that the tracks just need more time to load? Have you waited awhile to see if they appear?
Of course, you could have inserted the trigger MIDI track and started working already.

Thanks guys. I understand it is so weird. Also never tried right clicking and open that way. I will.
Hey at least I don't feel so lonely anymore :-) 
I guess I should also roll back because this just started with the last update or 2, no more than that.
I do have all the exe's. 
 

So waiting does not help. Right clicking does not help.
 
BUT, the big but....didn't realize this before because it happens so fast.
"All" the tracks are there when first opened and within a second or 2 they are gone. Drums always disappear, but not just the drums.
I think I have a ghost. Going to roll back and check 
 
BTW, I mean it only takes a second to insert a midi track and boom, they re appear, but still mind boggling.

Sometimes it can be an old template as well, I'm finding old bugs on old templates that are not showing up on new projects. like one song right now, the metronome does not work. on one other I setup a new project and imported the old tracks from an old project problem fixed... I don't know about midi though...
 
peace!

When the tracks have all loaded and you have the complete file there, save it as a midi file 1 with a different name. and see if you can open that one normally. May help ....

There is something that is happening as I have found a few hidden tracks popping up on older projects I open. Your friend for that is the track manager. After you open the midi file and if the tracks disapear, try opening the trck manager and see what's there. 
 
Another great trick I got from good ol' scook is you can make Sonar OPEN a midi file with TTS-1 
 
You need to go to Preferences/MIDI/Devices and select NONE for any output device. 
Now when you OPEN a GM midi file TTS-1 will load up and play the file all in a matter of seconds.