ModMatrix straight crash with ADD button

[DanH]

In my project using the Add button on the ModMatrixController floating tile causes an instant crash. Fine in a simple example. Debug sends me to this line (UtilityClasses.h:301):

	/** Provides write access to the main controller. Use this if you want to make changes. */
	MainController *getMainController() noexcept
	{
		jassert(controller != nullptr);
		return controller;
	}

Any idea what I'm looking for? Dodgy MatrixID? Dodgy Matrix Module?

Crash report (OSX) below:

Termination Reason:    Namespace SIGNAL, Code 11 Segmentation fault: 11
Terminating Process:   exc handler [8078]

VM Region Info: 0x18 is not in any region.  Bytes before following region: 4337582056
      REGION TYPE                    START - END         [ VSIZE] PRT/MAX SHRMOD  REGION DETAIL
      UNUSED SPACE AT START
--->  
      __TEXT                      1028a4000-1062d8000    [ 58.2M] r-x/r-x SM=COW  /Users/USER/Desktop/*/HISE Debug.app/Contents/MacOS/HISE Debug

Thread 0 Crashed:: JUCE Message Thread Dispatch queue: com.apple.main-thread
0   HISE Debug                    	       0x1028ae9d8 hise::ControlledObject::getMainController() + 32 (UtilityClasses.h:301)
1   HISE Debug                    	       0x102ee9eb0 hise::MatrixIds::Helpers::IntensityTextConverter::IntensityTextConverter(hise::MatrixIds::Helpers::IntensityTextConverter::ConstructData const&) + 52 (ModulationMatrixTools.cpp:627)
2   HISE Debug                    	       0x102eea320 hise::MatrixIds::Helpers::IntensityTextConverter::IntensityTextConverter(hise::MatrixIds::Helpers::IntensityTextConverter::ConstructData const&) + 36 (ModulationMatrixTools.cpp:630)
3   HISE Debug                    	       0x103262cc0 hise::MatrixBase::RowBase::setIntensityConverter(hise::JavascriptMidiProcessor*, int) + 424 (MatrixModulatorComponents.cpp:741)
4   HISE Debug                    	       0x1032615dc hise::MatrixBase::RowBase::updateIntensityConverter() + 788 (MatrixModulatorComponents.cpp:779)
5   HISE Debug                    	       0x1032604b8 hise::MatrixContent::Row::updateValue(juce::Identifier const&, juce::var const&) + 964 (MatrixModulatorComponents.cpp:489)