Did you load a drum map?

This is my next step (I'm software developer), I think I have to do:
- removing Sonar completely,
- deleting all registry entries
- reinstalling Sonar.
However, starting the piano roll view in Sonar is a calling a subprocess (in a dll), probably there is not a separate registry entry for it.
But I have no choice, just investing a lot of time into the reinstalling process.

Do you have the issue even in a new project created using the Normal project template?
 
1. Create new project.
2. Insert MIDI track.
3. Hit ALT+3.
 
Does the PRV open as expected?

Thanks for the advise. Yes, I did it.
In Sonar profeessional I created a new MIDI project, insert a MIDI track. No improvement.
The other options, event list, step sequencer shown up in the Multi Dock immediately.

@Resonant Serpent
 
Did you load a drum map?
 
No, I didn't.

@DRank
"Is it possible that the prv is minimized? Did you ever drag it out of the multidock? Just thinking outside the box."
No, I couldn't drag out it, because it doesn't exist (or it's invisible)
If you open a new window like event list or step sequencer, you see the name of the new window in the multidock - minimized or not.

The problem has been solved!!!
The solution is: Sonar WAV's use diverse MS C++ runtime versions (C++ redistributables 2005,2008,2010,2012,2013). This distributables have to be kept up to date by downloading them from Microsoft download center. I had an obsolete version.

I don't think I've ever heard/read of such an issue during my relatively long forum activity.
And I'd never have guessed that this problem was in any way wav-related, as it was about Piano Roll.
 
Well, who am I to comment :o) I have an XP-setup running SONAR 8.5.3 and it hasn't been updated or touched in any way in about ten years (except for the installing of 8.5). Even when I replaced the three HDDs  some five years ago I simply cloned the old ones, nothing else.