stevec
This probably isn't it based on everything else you've already tried, but, are the Input Echo buttons on the Aux Tracks enabled? 
 

yes, checked that already...that's why I (somehow) can hear auxes with plugins when I solo them.

As it stands I am at a loss to figure what could cause this. I have never had a problem with solo. 

could you have a hidden track soloed?

double check your routing man.
could have a track routed to a silent bus or something.
or its being feed in to a silent chain along the route
that's what it sounds like to me.
 
1- uncheck FX to turn them off completely.
2- then start by checking every output.
 

Just wondered if anyone found a solution as I'm getting this with every project! Using a Roland Vs100.

Cheers
Steve

Stevie P
Just wondered if anyone found a solution as I'm getting this with every project! Using a Roland Vs100.

Cheers
Steve

Tried everything with no luck...including all the suggestions above. I started a new project instead and export/import all tracks. Not good, Cakewalk.

like I said, its probably the routing as I use Aux tracks all the time.
 
1- uncheck FX to turn them off completely.
2- then start by checking every output.

Are your aux tracks in the track pane or buss pane?  If in the track pane try to engage echo button on aux track.

Stevie P
Just wondered if anyone found a solution as I'm getting this with every project! Using a Roland Vs100.

As I asked the OP, can you post an example project for download? It can be very difficult to troubleshoot routing problems without being able to see the project; there are so many ways to make something go unexpectedly silent.
 
And I wouldn't think this is hardware-specific, but if it is, playing the project on another system will help rule out that possibility.
 
Dave

I'll try and make the project available when I get chance, but I have found it happens when I use the global solo button, it seems I only get sound when everything is soloed like it's working in reverse, and nothing when it's not engaged. I have just found a way to get it to work again by first pressing Exclusive solo then solo and turning them off again, I'm at a loss it's not the only project that does this it's every time I use aux tracks?

Cheers
Steve.