Assertion in Juce 5 that wasn't in 4

General JUCE discussion
2

Don’t use a modal loop unless you really need to! They’ll be deprecated at some point in the future, and especially if you’re writing a plugin, you MUST NOT do this!

If you look at the example of this in the juce demo, you’ll see it does this:

        ColourSelector* colourSelector = new ColourSelector();
        colourSelector->setName ("background");
        colourSelector->setCurrentColour (findColour (TextButton::buttonColourId));
        colourSelector->setColour (ColourSelector::backgroundColourId, Colours::transparentBlack);
        colourSelector->setSize (300, 400);

        CallOutBox::launchAsynchronously (colourSelector, button.getScreenBounds(), nullptr);

…and that works without a problem.