--- a/gwt-client/src/main/java/org/dive4elements/river/client/client/ui/AbstractSingleItemPanel.java	Tue Jul 10 14:47:10 2018 +0200
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/client/ui/AbstractSingleItemPanel.java	Tue Jul 10 18:53:04 2018 +0200
@@ -226,20 +226,23 @@
 
         switch (this.type) {
         case multi:
-
-            final String[] sValues = sValue.trim().split(" ");
-            for (final String value : sValues) {
-                errors.addAll(this.validateSingleInput(value));
+            if (sValue != null) {
+                final String[] sValues = sValue.trim().split(" ");
+                for (final String value : sValues) {
+                    errors.addAll(this.validateSingleInput(value));
+                }
             }
             break;
         case limit5:
-            final String[] values = sValue.trim().split(" ");
-            if (values.length > 5) {
-                errors.add(this.MSG.error_limit_exceeded_salix());// TODO generalize if needed
-            }
-            for (int i = 0; i < values.length; i++) {
-                if (i < 5)
-                    errors.addAll(this.validateNumber(values[i]));
+            if (sValue != null) {
+                final String[] values = sValue.trim().split(" ");
+                if (values.length > 5) {
+                    errors.add(this.MSG.error_limit_exceeded_salix());// TODO generalize if needed
+                }
+                for (int i = 0; i < values.length; i++) {
+                    if (i < 5)
+                        errors.addAll(this.validateNumber(values[i]));
+                }
             }
             break;
         case single: