Firmware will download, not install
Hello,
Lubuntu is not officially supported.
But anyway my guess is issue is coming from another concern. Is Lubuntu usage related to the fact you’re running on a light hardware configuration ? According provided stack trace sounds to me multi core CPU is expected to speedup unzip process ... could you share your CPU hardware configuration ?
Single CPU hardware configuration sounds to me as a possible root issue (see attachment extracted from : http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/share/classes/java/util/concurrent/ThreadPoolExecutor.java )
Br,
cartu38