--- a/artifacts/src/main/java/org/dive4elements/river/artifacts/sinfo/tkhstate/DefaultBedHeights.java	Wed Jun 06 13:56:48 2018 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/sinfo/tkhstate/DefaultBedHeights.java	Wed Jun 06 14:15:58 2018 +0200
@@ -47,6 +47,25 @@
         final Collection<String> bedHeightNames = loadBedHeightDefaultsForRiver(this.river, problems);
 
         final List<BedHeight> defaultBedHeights = loadBedHeightsByName(this.river, bedHeightNames, problems);
+        if (defaultBedHeights.isEmpty()) {
+            problems.addProblem("sinfo.bedheightsfinder.nobedheightsforriver", this.river.getName());
+            return Collections.emptyList();
+        }
+
+        /* check for overlapping ranges, N2-search, but we expect only have small numbers of bed heights */
+        final List<BedHeight> result = new ArrayList<>(defaultBedHeights.size());
+
+        for (int i = 0; i < defaultBedHeights.size(); i++) {
+            final BedHeight bedHeight = defaultBedHeights.get(i);
+
+            final Range range = bedHeight.getRange();
+            final NumberRange bedRange = new NumberRange(range.getA(), range.getB());
+
+            if (overlapsRange(bedRange, defaultBedHeights, i + 1)) {
+                problems.addProblem("sinfo.bedheightsfinder.overlappingrange", bedHeight.getDescription());
+            } else
+                result.add(bedHeight);
+        }
 
         final List<BedHeight> validBedHeights = new ArrayList<>(defaultBedHeights.size());
 
@@ -61,21 +80,6 @@
                 validBedHeights.add(bedHeight);
         }
 
-        /* check for overlapping ranges, N2-search, but we expect only have small numbers of bed heights */
-        final List<BedHeight> result = new ArrayList<>(defaultBedHeights.size());
-
-        for (int i = 0; i < defaultBedHeights.size(); i++) {
-            final BedHeight bedHeight = validBedHeights.get(i);
-
-            final Range range = bedHeight.getRange();
-            final NumberRange bedRange = new NumberRange(range.getA(), range.getB());
-
-            if (overlapsRange(bedRange, validBedHeights, i + 1)) {
-                problems.addProblem("sinfo.bedheightsfinder.overlappingrange", bedHeight.getDescription());
-            } else
-                result.add(bedHeight);
-        }
-
         return result;
     }