diff --git a/li.strolch.model/src/main/java/li/strolch/model/Resource.java b/li.strolch.model/src/main/java/li/strolch/model/Resource.java
index b5a4ec006..db4886fdd 100644
--- a/li.strolch.model/src/main/java/li/strolch/model/Resource.java
+++ b/li.strolch.model/src/main/java/li/strolch/model/Resource.java
@@ -172,8 +172,10 @@ public class Resource extends GroupedParameterizedElement implements StrolchRoot
 
 		super.fillClone(clone);
 
-		for (StrolchTimedState<IValue<?>> timedState : this.timedStateMap.values()) {
-			clone.addTimedState(timedState.getClone());
+		if (this.timedStateMap != null) {
+			for (StrolchTimedState<IValue<?>> timedState : this.timedStateMap.values()) {
+				clone.addTimedState(timedState.getClone());
+			}
 		}
 
 		return clone;