Whiskey tango foxtrot!?
 
Ive imported a guitar pro midi file, playing, looking good in staff view, but it cannot display tab.
 
Box is grey, no explanation.
 
 
 
 

Are you in track view or prv?
Not sure it makes a difference, but a thought?

track view, dont know what prv is.
 
Now I know why Sonar failed.

Give yourself time to learn how to use it.
Last time I used this feature was long ago, but it worked fine for decades so I expect it does now too.

PRV is Cakewalk's Piano Roll View.

I just opened staff view with a midi track containing note events
Right clicked in the resulting window
Selected Layout
A dialog opened where I clicked the box next to Display Tablature

Now there's a lower staff displaying tablature.

Works fine...

I do the same thing, that box for displaying tab is greyed out!

Mine was also greyed out until I selected Treble clef instead of Treble/Bass clefs. Then Tab worked.

200bpm
 
Now I know why Sonar failed.

Comments like that are not going to get you a lot of friends around here, or much help either...