Dear Mayeul,
We are migrating forum so now it’s better to ask your question to the community Image.sc forum
Still to quikcly reply you here: incoming Icy 2.1 will fix the launching issue on Catalina but about the 3D VTK view, i think it’s somehow related to this issue. Unfortunately right now it seems that the 3D rendering with OSX Catalina doesn’t work correctly, we are currently investigating the problem (may be related to some incompatiblities with the used openGL library to build up VTK) but it may take sometime to fix it (we will probably need to upgrade to a new VTK version).
Best,
– Stephane