The netCDF-Java 5.9.1 release had an issue where the toolsUI jar was missing a critical properties file, preventing the application from launching. This has been fixed in a new toolsUI-only release, v5.9.1.1, available on the NSF Unidata netCDF-Java downloads page and GitHub. Additionally, netCDF-Java command-line utilities and toolsUI are now available via conda-forge thanks to community efforts!