Please be more specific about "few similar errors" - some log or screenshots are welcomed.

Here the windows exception:

java.io.FileNotFoundException: D:\Documents and Settings\User\.netbeans\dev\modules\ext\serverfx.jar (The system cannot find the file specified)
	at java.util.zip.ZipFile.open(Native Method)
	at java.util.zip.ZipFile.<init>(ZipFile.java:114)
	at java.util.jar.JarFile.<init>(JarFile.java:133)
	at java.util.jar.JarFile.<init>(JarFile.java:112)
	at org.netbeans.JarClassLoader$JarSource$1.call(JarClassLoader.java:443)
	at org.netbeans.JarClassLoader$JarSource$1.call(JarClassLoader.java:440)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at org.netbeans.JarClassLoader$JarSource.getJarFile(JarClassLoader.java:456)
	at org.netbeans.JarClassLoader$JarSource.resource(JarClassLoader.java:489)
	at org.netbeans.Archive.getData(Archive.java:196)
	at org.netbeans.JarClassLoader$JarSource.doGetResource(JarClassLoader.java:469)
	at org.netbeans.JarClassLoader$Source.getResource(JarClassLoader.java:318)
	at org.netbeans.JarClassLoader.findResource(JarClassLoader.java:254)
	at org.netbeans.core.startup.NbInstaller.loadLayers(NbInstaller.java:566)
	at org.netbeans.core.startup.NbInstaller.load(NbInstaller.java:328)
	at org.netbeans.ModuleManager.enable(ModuleManager.java:929)
	at org.netbeans.core.startup.ModuleList.installNew(ModuleList.java:315)
	at org.netbeans.core.startup.ModuleList.trigger(ModuleList.java:251)
	at org.netbeans.core.startup.ModuleSystem.restore(ModuleSystem.java:283)
	at org.netbeans.core.startup.Main.getModuleSystem(Main.java:169)
	at org.netbeans.core.startup.Main.start(Main.java:299)
	at org.netbeans.core.startup.TopThreadGroup.run(TopThreadGroup.java:111)
[catch] at java.lang.Thread.run(Thread.java:619)

Created attachment 93839 [details]
log

It's strange: sometimes on Linux IDE closes without any GUI sometimes shows GUI dialog box with exception then closes.
Log attached.

That gives us Issue 159093 back.

x86 affected as well. Will check sparc.
It's even strange windows allows IDE to start :)

The errors are real; the dotfx module is broken: its Class-Path header points to the wrong JAR. Jirka (?) please see if this module can be removed from AU until it can be fixed.

The dialog on Windows (FNFE rather than ZipException) I can fix, as well as the occasional dialogs on Linux (closing over-limit JARs in JarSource.opened): core-main #aebca52f64df

The abrupt exit of the JVM is trickier. Shutdown hooks do not get run, nor is any stack trace available, so System.err.println is the only way to figure out what does and what does not get run. Fixing the Class-Path does not prevent the problem. Commenting out Services and Toolbars in the dotfx layer allows the IDE to run, but then expanding its node in the Services tab throws

org.netbeans.ExitSecurityException: Illegal attempt to exit early
	at org.netbeans.TopSecurityManager.checkExitImpl(TopSecurityManager.java:193)
	at org.netbeans.TopSecurityManager$PrivilegedCheck.run(TopSecurityManager.java:683)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.netbeans.TopSecurityManager$PrivilegedCheck.check(TopSecurityManager.java:708)
	at org.netbeans.TopSecurityManager$PrivilegedCheck.checkExit(TopSecurityManager.java:696)
	at org.netbeans.TopSecurityManager.checkExit(TopSecurityManager.java:154)
	at java.lang.Runtime.exit(Runtime.java:88)
	at java.lang.System.exit(System.java:904)
	at com.dotfx.netbeans.RepositoryFacade.<init>(RepositoryFacade.java:77)
	at com.dotfx.netbeans.RepositoryFacade.getInstance(RepositoryFacade.java:35)
	at com.dotfx.netbeans.dotFXControl.<init>(dotFXControl.java:60)
	at com.dotfx.netbeans.dotFXControl.getInstance(dotFXControl.java:50)
	at com.dotfx.netbeans.ServerNode.<init>(ServerNode.java:55)
	at com.dotfx.netbeans.dotFXChildren.createNodes(dotFXChildren.java:61)

so very likely RepositoryFacade.<init>'s illegal use of System.exit is to blame for the trouble. (TSM's System.exit prevention logic may happen too late if the other layer folders are enabled?) javap seems to indicate that it croaks if !System.getProperty("os.name").startsWith("Windows"). If this module cannot run on non-Windows platforms, it should simply use

OpenIDE-Module-Requires: org.openide.modules.os.Windows

to express this declaratively and prevent AU from even trying to install it on Linux.

Wayne, can you please try to fix this problem? If the problem is not resolved in a timely manner, we will have to withdraw the dotFX plugin from the Development Update Center. Thanks for your help!

Integrated into 'main-golden', will be available in build *201002050200* on http://bits.netbeans.org/dev/nightly/ (upload may still be in progress)
Changeset: http://hg.netbeans.org/main/rev/aebca52f64df
User: Jesse Glick <jglick@netbeans.org>
Log: Improved fix for #159093: over-strict logging of bad Class-Path declarations.
Discovered as part of diagnosis of problems in dotfx module (#180259).

The same here, only on version 6.8. IDE shuts down only, does not restart. I'm using Win 7.

Confirmed on Windows 7.

Module dotfx was removed from Dev UC.

Yes, thank you Robert. Wayne, don't hesitate to ask [1] for publishing your plugin on the Update Center once you fix the dependency issue. Thanks!

[1] http://www.netbeans.org/community/guidelines/au-request-form.html

Verified with 201004140201