Solo a track and it plays solo, as expected.
 
Click the DIM button and you can hear the other tracks faintly as expected BUT the soloed tracks are now muted. Can't hear them at all. Dim Solo is broken!

Working here as expected. I was using it a few days ago.
Possibly a routing issue ? I'll give another test a little later.

Opened another project and it works as expected. Seems to be project specific. So easy to corrupt these cwp files I guess.

Also working here as expected. In 17 years of using SONAR, I've had one corrupted project. Intermittent, non-reproducible problems, as well as projects that "corrupt" easily, suggest that it's time to check your RAM.

YMMV. In my 17 years of using Sonar, it's been on 6 or 7 different systems and everyone produced a few corrupted projects. I can "save-as" a project with 20-50 versions while doing a ton of edits to each one, so it's not surprising to me if one of those gets corrupted now and then. Since only one project is behaving this way and I've actually been able to trace other corruptions back to a singular project I believe it's more likely an "evolutionary" development rather than a hardware issue. Only one of my systems actually had bad ram and it was replaced under warranty.

ya I've only had 1 or 2 corrupt projects as well and those projects were older projects opened in newer versions so I can really chalk it up to corruption.
 
Was this is an older project opened in a newer version of Sonar ?

Info on causes of file corruption from SONAR's documentation:
 
Data corruption on a DAW can occur due to various reasons, a few of which include:
 
*  Your hard drive might suffer data loss.
*  Windows delayed writes might fail leading to data corruption.
*  Many hard disks have a “write through cache” buffer for efficiency. Occasionally this write through buffer might not get flushed due to a driver error or system crash. In such cases data might not be flushed to your hard driver causing corrupt files (SONAR requests Windows to flush this buffer after a file save operation).
*  A plug-in can corrupt SONAR's memory space causing invalid data to be written to disk when the project is saved.

chuckebaby
Was this is an older project opened in a newer version of Sonar ?

Most likely. All my projects were started years ago with older versions. When opened they get resaved several times during editing. After so many saves they get "saved as" to the next sequential number. No new projects have been created in SPlat. Even so, SPlat is now a "singular" version being upgraded every month to a "new" version so even new projects may be affected by this over time.
 
Whatever's causing the corruption, it's my experience that the more one is edited and saved the more likely it will become corrupted some how.
 
This is another reason I keep older versions installed. That said, SPlat upgrades appear to be affecting the behavior of older versions.

I routinely open up old projects in Platinum, then strip out selected tracks to create new music beds and backgrounds for videos. No problems yet...

Together we keep the universe balanced.