Importing MIDI doesn't have an instrument added

[C T]

On my old system, any MIDI imported could be immediately played with a built in (basic) piano vst. But now on my current system I need to do the whole adding another instrument track and doing that before I can hear anything. The MIDI tracks are now only MIDI where as one of them used to have a synth instrument already applied. I use Musescore 4 to export my MIDIs. 

Below is how Cakewalk would look when opening a MIDI file.

However, now it looks like this:

Is this because I haven't installed all the built-in instruments or something?

Additionally, I'm sure it was this VST called "TTS-1" that would automatically load. But I no longer have it. How do I install this?????

[57Gregy]

Roland asked Cakewalk to stop including TTS-1 with their DAWs.
You can't get it with any new program installs.
If your old system has an older version of Cakewalk products since around 2006, you should still have it available there.
If you do have any older products in your account and they are downloadable programs, you can download it and get TTS-1 on your new computer.
There are several threads around here concerning replacements for TTS-1. Check around for them; you might find something better, or at least equivalent.

[Sock Monkey]

Yep Sonar is now one of the very few Daw’s that doesn’t have a simple GM player anymore. Wasn’t totally the developers fault as Greg said Roland owned it and wanted it removed. 
 

The TTS-1 was becoming very unstable and causing crashes anyway so it was a good decision. 

But what I don’t understand is why they didn’t make it a priority to use the same instruments as Cakewalk Next is using?  They are a step up from TTS-1. 
I don’t think they would do that for Cakewalk but they most certainly should for Sonar. 

For now I recommend you use the VST synth font 64 player. The demo is free and then a license I think is only $20. I got it free with Band in. Box. But you will still need to manually insert it.