In sendPropertyChangeMessage() read access violation

I get a read access violation, does anyone have a hint what the problem might be?

void sendPropertyChangeMessage (const Identifier& property, ValueTree::Listener* listenerToExclude = nullptr)
    {
        ValueTree tree (*this);
        callListenersForAllParents (listenerToExclude, [&] (Listener& l) { l.valueTreePropertyChanged (tree, property); });
    }

It occurs, when running my plugin in the Juce Plugin Host. When running it as Standalone or running it inside Reaper, no problems occure?

After some debugging, I see:
when I add my plugin to the JucePluginHost, it calls the constructor of the PluginEditor and delets it afterwards(I do not see the Gui popping up).
When I press right click on the Plugin in the JucePluginHost, the same happens. (why?)

When I select “Show Plugin Gui”, the constructor is called again, the Gui gets visible, but the Plugin breaks (acces violation at sendPropertyChangeMessage() and sometimes because of a changed Paramter).

In Reaper and as standalone the load and save works fine for properties and parameters. But I noticed that the plugin breaks also, when I reopen the plugin in Reaper, after having closed the Gui (using the window-x/close-button).