I guess it is generated by Sonar 7.
The "placeholder" for synthes are there ("Synth rack" folder after the conversion), but related MIDI tracks are "misplaced" in the structure and synthes are not resurrected at all, that I have to fix (I guess the bug is triggered by frozen synthes).
I will let you know when I manage to improve the conversion using this example (not next days, I hope around the end of the next week).
PS. You can open all old projects in the latest Sonar, which is now called "Cakewalk by Bandlab":
https://www.bandlab.com/products/cakewalk
They have made the latest Sonar Platinum engine (without most plug-ins) completely free to use (not a trial).
Note that it is huge installation compare to REAPER and hard to clean completely after un-installing.