JUCE_LIVE_CONSTANT error

Hello,
sorry for not clear topic name, but I was not sure how to explain it in two words.

I always use JUCE_LIVE_CONSTANT and it is great feature for designing. But suddenly it gives me error always. Inside CoreGraphicsContext::addTransform() I get EXC_BREAKPOINT on line:
jassert (getPhysicalPixelScaleFactor() > 0.0f);

And it because inside getPhysicalPixelScaleFactor() I get NULL on line:
CGContextGetUserSpaceToDeviceSpaceTransform (context.get());

And it happens only if I move slider (or change value) on JUCE_LIVE_CONSTANT panel.
It happens even if I don’t use the result of JUCE_LIVE_CONSTANT.

I tried to move JUCE_LIVE_CONSTANT into various part of code but nothing helps. I even tried to restart xCode, rebuilt xCode project by Projucer, and even restart my computer. And nothing helps.

But about 1 hour ago everything was working perfectly.

So what could be wrong?

For any help great thanks in advance.
Best regards