Corky, Coretto and AdoptOpenJDK have this issue on Mac 10.14 and 10.15 for sure. The Azul Zulu version 8 and Oracle's Java SE 8 do NOT suffer from this issue. I am able to reproduce this at will. (I have not been able to reproduce it on Windows 10 Education or Pro. All versions seem to work without condition.) I am still researching why this is the case, but the symptoms I see are related to writing the class file. DrJava cannot write the class file, but using javac on the command line is successfull....