Hi Naoki, could you tell us which Eclipse/JDK version combination you use to run AmaterasUML (or modeler)? I am asking because Eclipse 2020-06 (PDE variant) and OpenJDK 11, with AmaterasModeler 1.1...

Last known Eclipse/JDK version with which AmaterasUML works? · Issue #12 · takezoe/amateras-modeler