When multiple users work on the same Machine, VisualVM will only work for the first user starting it properly.
All other users can't save snapshots.

Since snapshots are saved in /tmp/visualvm.dat/ this folder belongs to the first user and any other user can't write to it.

A workaround would be to add the username to the tmp folder, e.g. /tmp/visualvm.dat_USERNAME.

Here's the error stacktrace:

java.lang.IllegalStateException: Cannot create storage directory /tmp/visualvm.dat/localhost_24976
	at com.sun.tools.visualvm.core.datasource.Storage.getDirectory(Storage.java:125)
[catch] at com.sun.tools.visualvm.profiler.ProfilerSnapshotAction$SnapshotsListenerImpl.snapshotSaved(ProfilerSnapshotAction.java:120)
	at org.netbeans.modules.profiler.ResultsManager$10.run(ResultsManager.java:1060)
	at org.netbeans.lib.profiler.common.CommonUtils.runInEventDispatchThread(CommonUtils.java:61)
	at org.netbeans.modules.profiler.ResultsManager.fireSnapshotSaved(ResultsManager.java:1057)
	at org.netbeans.modules.profiler.ResultsManager.saveSnapshot(ResultsManager.java:897)
	at org.netbeans.modules.profiler.ResultsManager.saveSnapshot(ResultsManager.java:961)
	at org.netbeans.modules.profiler.ProfilerControlPanel2$ResultsSnippetPanel.snapshotTaken(ProfilerControlPanel2.java:934)
	at org.netbeans.modules.profiler.ProfilerControlPanel2$Listener.snapshotTaken(ProfilerControlPanel2.java:222)
	at org.netbeans.modules.profiler.ResultsManager$11.run(ResultsManager.java:1074)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.awt.EventQueue$3.run(EventQueue.java:703)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)