Bug 242433

Sometimes (usually when the system is overloaded) when starting NetBeans the taskbar is completely or partially missing. Given the ide logs this seems to be caused by accessing the UI from a background thread (also my experience is that accessing UI from background thread produces strange class cast exceptions). The log entry which is relevant seems to be this:

SEVERE [org.openide.util.RequestProcessor]: Error in RequestProcessor org.openide.loaders.FolderInstance$1R
java.lang.ClassCastException: javax.swing.plaf.nimbus.NimbusIcon cannot be cast to java.awt.Font
	at javax.swing.plaf.nimbus.NimbusStyle.getFontForState(NimbusStyle.java:573)
	at javax.swing.plaf.synth.SynthStyle.installDefaults(SynthStyle.java:933)
	at javax.swing.plaf.nimbus.NimbusStyle.installDefaults(NimbusStyle.java:231)
	at javax.swing.plaf.synth.SynthStyle.installDefaults(SynthStyle.java:916)
	at javax.swing.plaf.synth.SynthLookAndFeel.updateStyle(SynthLookAndFeel.java:265)
	at javax.swing.plaf.synth.SynthToolBarUI.updateStyle(SynthToolBarUI.java:111)
	at javax.swing.plaf.synth.SynthToolBarUI.installDefaults(SynthToolBarUI.java:77)
	at javax.swing.plaf.basic.BasicToolBarUI.installUI(BasicToolBarUI.java:144)
	at javax.swing.JComponent.setUI(JComponent.java:664)
	at javax.swing.JToolBar.setUI(JToolBar.java:181)
	at javax.swing.JToolBar.updateUI(JToolBar.java:192)
	at javax.swing.JToolBar.<init>(JToolBar.java:158)
	at org.openide.awt.ToolbarWithOverflow.<init>(ToolbarWithOverflow.java:140)
	at org.openide.awt.ToolbarWithOverflow.<init>(ToolbarWithOverflow.java:106)
	at org.openide.awt.ToolbarWithOverflow.<init>(ToolbarWithOverflow.java:93)
	at org.openide.awt.Toolbar.<init>(Toolbar.java:139)
	at org.openide.awt.ToolbarPool$Folder.acceptFolder(ToolbarPool.java:482)
	at org.openide.loaders.FolderInstance.acceptDataObject(FolderInstance.java:442)
	at org.openide.loaders.FolderInstance.defaultProcessObjects(FolderInstance.java:798)
	at org.openide.loaders.FolderInstance.access$000(FolderInstance.java:103)
	at org.openide.loaders.FolderInstance$1R.init(FolderInstance.java:693)
	at org.openide.loaders.FolderInstance$1R.run(FolderInstance.java:720)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1432)
[catch] at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2042)