Ulf here from Steinberg.
Cubase 8 got released in December and we receive lots of customer reports on Cubase crashing when opening the mixer window by pressing F3. Looking at the crash dumps we get, it always points into certain plug-ins that are causing the trouble.
Having further analyzed these crashes, it actually turns out that JUCE is causing them, because in dispatchMessageFromlParam() the reinterpret_cast on lParam succeeds, but the object behind it is invalid and so message->messageCallback() results in an access violation.
Cubase itself doesn't use JUCE, but we have one special plug-in that uses it and with this plug-in I can also reproduce that issue (that's also the reason why I can pin point to it in the debugger.) Our plug uses JUCE 3.0.8.
Have you heard of such issues before and will you look into it?
I can help in providing more details and also provide you with a temporary Cubase 8 license in case you need it.
As said, it's plug-ins from various vendors that expose this behaviour and from our perspective it is very serious, because it makes Cubase very unstable. and it doesn't help Cubase users to tell them not to use JUCE based plug-ins.
Also, if you have a fix it would be best to notify all JUCE developers of such fix, so that they can publish updated plug-ins in order that they run stable with Cubase 8 again.