Do you know why I get “No matching constructor for initialization of ‘StandaloneFilterWindow’” when I use juce_DeclareSingleton(StandaloneFilterWindow, false) in my class (class StandaloneFilterWindow : public ApplicationProperties) ?
Maybe you didn’t added “public:” where you should have or maybe you declared none-empty constructor without explicitly adding also an empty constructor.
Remember guys, singletons should only be used as a last resort. If you can find any other possible way of handling ownership of that object, then you should do so.