I've searched this forum & Googled this issue without any luck but I'll apologise now if this has been well documented but I couldn't find it.  I did find several complaints about compatibility issues with older projects though but none relating to my issue.
 
Basically, when I open older projects such as those created with Producer 8.5, selecting tracks in the mixing console doesn't automatically mirror the track strip in the Track Inspector Strip.  Also, my ProChannel Tab doesn't work either!  The Track Inspector stays stuck on the first track which gets loaded when I open the project.  The ProChannel arrow on the mixing console works fine though, clicking it expands the channel strip as expected.

I have no such issues with projects created with Producer X1 Expanded or Producer X2a, everything works as normal.
 
I should add at this point that I'm using Producer X2a as I haven't upgraded yet, due to being involved in several projects & not wanting to upset any works in progress.
 
Is this a known issue?  If so, are there any workarounds?  Thanks. 

Try updating the project by saving under a new name. I have not seen this behavior. I have projects far older than 8.5 and I have no problem with them. 

Hi John.
 
Thanks for the reply, I've already tried that & it didn't work.  :-(
 
What version of Sonar are you using?

The latest Platinum. That shouldn't matter. Which version are you using? 

I'm using Producer X2a.  I've been going through all my old projects & some are fine & some are not.
 
Interestingly, I have a small project which I started for fun in Prod 8.5 which just has a few MIDI sections, no audio or VST FXs & that does it so it's not some weird plugin problem by the look of it, I think?

I would doubt that myself. 8.5 did not have the PC. Check and see if by change the PC is showing in tracks that seem not to be the right one. There is also a way to keep the track Inspector locked to one track. This maybe engaged.
 
To lock the Track Inspector to a specific track or bus
Be default, the Track Inspector dynamically updates to show the current track. However, you can choose to
always show a specific track or bus regardless of which track is current.
1. Click the track or bus you want to show in the Track Inspector.
2. Click the Track Name control in the Track Inspector and select Lock the current track or bus from the dropdown menu.
To unlock the track or bus, select Lock the current track or bus from the menu again. 
 
I don't know if this will help but its a shot. 

John, you're a star as that sorted it.
 
I did see this in the manual but I couldn't work out where I was meant to click but reading that again in your post made sense this time.
 
The bit I didn't get was "Click the Track Name control in the Track Inspector" as I was clicking on the console strip & then around the inspector strip but not actually on the bar at the bottom where the track name sits!!!  That explains why I couldn't see the option to select "Lock the current track or bus" from the menu!
 
This was clearly a case of read the manual "CAREFULLY"!
 
Thank you very much. :-)

You just made my day. I am so glad it worked for you.