VisualVM default gtk plaf not working on a default Ubuntu install

[JeromeA]

Describe the bug
When running VisualVM on a default Ubuntu install, the UI seems to work, but any attempt to use the sample or the profiler silently fails.

To Reproduce

1. Install VisualVM on a minimal Ubuntu desktop configuration.
2. Start VisualVM, connect to a running app, and start the profiler.
3. Nothing happens in the UI, an exception is raised in the logs.

VisualVM log
messages.log

Version

• OS: Ubuntu 21.04
• System: Linux (5.11.0-38-generic) , amd64 64bit
• JDK: OpenJDK 64-Bit Server VM (build 17+35-Ubuntu-121.04)
• VisualVM: 2.1.1 (Build 210920); platform 20210621-2172674416

Workaround
visualvm --laf Metal works.

[thurka]

Problem seems to be caused by changes in JDK. JDK 15 and older works fine, while JDK 16 and newer fails with above NPE. So another workaround is to run VisualVM on JDK 15 or older.

[thurka]

This regression is caused by
JDK-8041705 - Bugs in DefaultTreeCellRenderer.updateUI()

[thurka]

Fixed in master.