Due to Oracle’s end of public support of Java8 for commercial users, we’ve changed the bundled JRE for Astah to AdoptOpenJDK.
If your company security policy does not allow a use of app with un-supported JRE, update to version 1.5, then you will be all set.
-  We switched the bundled JRE from Oracle Java to AdoptOpenJDK.
-  [Update Diagram] menu is added to adjust objects’ size and layout on the diagram. Since we’ve changed a drawing library from this version, diagrams created with earlier versions may look different on this version.
This [Update Diagram] menu fixes the difference to make the diagram look right.