diff --git a/structr-core/src/main/java/org/structr/schema/parser/DatePropertyParser.java b/structr-core/src/main/java/org/structr/schema/parser/DatePropertyParser.java
index <HASH>..<HASH> 100644
--- a/structr-core/src/main/java/org/structr/schema/parser/DatePropertyParser.java
+++ b/structr-core/src/main/java/org/structr/schema/parser/DatePropertyParser.java
@@ -68,7 +68,7 @@ public class DatePropertyParser extends PropertyParser {
 	@Override
 	public void parseFormatString(final Schema entity, String expression) throws FrameworkException {
 
-		if (expression.length() == 0) {
+		if (expression == null || expression.length() == 0) {
 			errorBuffer.add(SchemaNode.class.getSimpleName(), new InvalidPropertySchemaToken(expression, "invalid_date_pattern", "Empty date pattern."));
 			return;
 		}
Added null check (was in outer method before)