diff --git a/modules/web/src/com/haulmont/cuba/web/gui/components/WebAbstractList.java b/modules/web/src/com/haulmont/cuba/web/gui/components/WebAbstractList.java
index 616809fd1f..162c0f0600 100644
--- a/modules/web/src/com/haulmont/cuba/web/gui/components/WebAbstractList.java
+++ b/modules/web/src/com/haulmont/cuba/web/gui/components/WebAbstractList.java
@@ -102,7 +102,7 @@ public abstract class WebAbstractList<T extends AbstractSelect, E extends Entity
         Set itemIds = new HashSet();
         for (Entity item : items) {
             if (!datasource.containsItem(item.getId())) {
-                throw new IllegalStateException("Datasource doesn't contain items");
+                throw new IllegalStateException("Datasource doesn't contain item to select: " + item);
             }
             itemIds.add(item.getId());
         }