Update March 2020 - this should be fixed in NetBeans 11.2 and later, released on 25th October 2019. Details in the bug report.
This is caused by a recent change in the JDK. Please see this question for more information. Although the question relates to JDK11 the same change was made to JDK8 and the same solution (it is a work-around, really) applies.
Edit your netbeans.conf
(you will find this in your netbeans directory under etc
) to add -J-Djdk.lang.Process.allowAmbiguousCommands=true
to the netbeans_default_options
key. You can edit with notepad but you might need to do it as an Administrator depending on how you installed NB.
For example, mine looks like:
# JDK 11 made GTK 3 default on Linux. Unfortunately it makes
# NetBeans ugly on Linux with the default GTK+ Look and Feel,
# as a workaround -J-Djdk.gtk.version=2.2 has been added to the
# default command line arguments.
# (see: https://issues.apache.org/jira/browse/NETBEANS-1344)
#
netbeans_default_options="-J-Djdk.lang.Process.allowAmbiguousCommands=true -J-XX:+UseStringDeduplication -J-Xss2m -J-Djdk.gtk.version=2.2 -J-Dapple.laf.useScreenMenuBar=true -J-Dapple.awt.graphics.UseQuartz=true -J-Dsun.java2d.noddraw=true -J-Dsun.java2d.dpiaware=true -J-Dsun.zip.disableMemoryMapping=true -J-Dplugin.manager.check.updates=false -J-Dnetbeans.extbrowser.manual_chrome_plugin_install=yes -J--add-opens=java.base/java.net=ALL-UNNAMED -J--add-opens=java.base/java.lang.ref=ALL-UNNAMED -J--add-opens=java.base/java.lang=ALL-UNNAMED -J--add-opens=java.base/java.security=ALL-UNNAMED -J--add-opens=java.base/java.util=ALL-UNNAMED -J--add-opens=java.desktop/javax.swing.plaf.basic=ALL-UNNAMED -J--add-opens=java.desktop/javax.swing.text=ALL-UNNAMED -J--add-opens=java.desktop/javax.swing=ALL-UNNAMED -J--add-opens=java.desktop/java.awt=ALL-UNNAMED -J--add-opens=java.desktop/java.awt.event=ALL-UNNAMED -J--add-opens=java.prefs/java.util.prefs=ALL-UNNAMED -J--add-opens=jdk.jshell/jdk.jshell=ALL-UNNAMED -J--add-modules=jdk.jshell -J--add-exports=java.desktop/sun.awt=ALL-UNNAMED -J--add-exports=java.desktop/java.awt.peer=ALL-UNNAMED -J--add-exports=java.desktop/com.sun.beans.editors=ALL-UNNAMED -J--add-exports=java.desktop/sun.swing=ALL-UNNAMED -J--add-exports=java.desktop/sun.awt.im=ALL-UNNAMED -J--add-exports=jdk.internal.jvmstat/sun.jvmstat.monitor=ALL-UNNAMED -J--add-exports=java.management/sun.management=ALL-UNNAMED -J--add-exports=java.base/sun.reflect.annotation=ALL-UNNAMED -J--add-exports=jdk.javadoc/com.sun.tools.javadoc.main=ALL-UNNAMED -J-XX:+IgnoreUnrecognizedVMOptions"
Thanks to @Sephiroth for providing the answer.