Have just upgraded to El Capitan 10.11.1, Xcode 7.1.1, JUCE 4.0.2, VST 365 and getting a bunch of warnings e.g. AudioHardwareServiceGetProperty is deprecated: first deprecated in OS X 10.11.
As I'm unable to proceed on Windows 10 while you're working on build stuff for Grapefruit Juce, I've switched to Mac and I've got the same issue mentioned here.
You said to set compatibility level to pre-10.11. How do I do this? Is this something I do in Xcode? In Juce? In Mac OS settings?
Will this also deal with fatal errors "enumerator value evaluates to -2147483648, which cannot be narrowed to type 'uint32_t' (aka unsigned int)"?
I have tried going to the Config tab > XCode (MacOSX) and setting the OSX Deployment target to 10.10 but this doesn't change anything so I'm probably looking at the wrong thing.
As a newbie to Juce, this is frustrating as I've been unable to get started in either Windows 10 or OS X El Capitan so far. :-(
Unless I've misunderstood something, it seems I can ignore the warnings and fatal errors that Projucer produces and just go to opening in IDE and compile from there.
If you pull the latest version from GIT, we've added a workaround for the enum problem (which is actually a Clang/Apple bug, not technically our fault!)