And running from the command line results in the following error:
patchnotification.bat -c -i all
================================================================================
ArcGIS Enterprise Patch Notification
================================================================================
Collecting patch info for:
ArcGIS Server 10.8.1..............
Exception in thread "main" java.lang.NullPointerException
at com.esri.arcgis.server.tools.patchnotification.install.PatchFileDownloader.validateDownloadURL(PatchFileDownloader.java:143)
at com.esri.arcgis.server.tools.patchnotification.install.PatchFileDownloader.<init>(PatchFileDownloader.java:63)
at app.gui.installer.InstallItem.<init>(InstallItem.java:76)
at app.gui.ConsoleHandler.installAvailablePatches(ConsoleHandler.java:83)
at app.Main.main(Main.java:303)