BEFORE you copy transitions from a previous version you MUST run VideoStudio at least once to prime the various libraries.
Then you can close VideoStudio, copy the transitions and other material from previous versions and then open VideoStudio again.
Now it will add the extra transitions to the primed libraries.
If you have copied the transitions over before you opened VideoStudio for the very first time then you need to remove ALL the transitions.
Delete the library files (You find their locations
here). Run the VideoStudio installation program again and select the "Repair" option to restore the original transitions you deleted above.
Alternatively if you followed my suggestion of renaming the original folder containing your VFX or VFT files then simply restore them from that folder (Which is your backup)
1. Before you copy any transitions from the older vfx_plug directory - rename the existing one.
C:\Program Files\Corel\Corel VideoStudio 12\vfx_plug
rename to
C:\Program Files\Corel\Corel VideoStudio 12\vfx_plug_X2
Now proceed as I stated at the start of this post. Open VideoStudio to prime the libraries, close VideoStudio. Copy the other stuff over then open VideoStudio again.
I have now edited the procedure to include this important step.