diff --git a/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/internal/p2/engine/SimpleProfileRegistry.java b/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/internal/p2/engine/SimpleProfileRegistry.java
index 9e02654..c8309f2 100644
--- a/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/internal/p2/engine/SimpleProfileRegistry.java
+++ b/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/internal/p2/engine/SimpleProfileRegistry.java
@@ -38,7 +38,7 @@
 
 public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 
-	private static final String SIMPLE_PROFILE_REGISTRY_INTERNAL = "_simpleProfileRegistry_internal_";
+	private static final String SIMPLE_PROFILE_REGISTRY_INTERNAL = "_simpleProfileRegistry_internal_"; //$NON-NLS-1$
 	private static final String ECLIPSE_IGNORE_USER_CONFIGURATION = "eclipse.ignoreUserConfiguration"; //$NON-NLS-1$
 	private static final String PROFILE_REGISTRY = "profile registry"; //$NON-NLS-1$
 	private static final String PROFILE_PROPERTIES_FILE = "state.properties"; //$NON-NLS-1$
@@ -881,7 +881,7 @@
 
 	public synchronized void unlockProfile(IProfile profile) {
 		if (profile == null)
-			throw new IllegalArgumentException(NLS.bind(Messages.profile_not_registered, profile.getProfileId()));
+			throw new IllegalArgumentException(NLS.bind(Messages.profile_not_registered, "")); //$NON-NLS-1$
 		internalUnlockProfile(profile);
 	}