Index: trunk/src/org/openstreetmap/josm/gui/dialogs/validator/ValidatorTreePanel.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/dialogs/validator/ValidatorTreePanel.java	(revision 14855)
+++ trunk/src/org/openstreetmap/josm/gui/dialogs/validator/ValidatorTreePanel.java	(revision 14856)
@@ -162,4 +162,8 @@
         sortErrors(errors);
 
+        // Remember first selected tree row
+        TreePath selPath = getSelectionPath();
+        int selRow = selPath == null ? -1 : getRowForPath(selPath);
+
         // Remember the currently expanded rows
         Set<Object> oldSelectedRows = new HashSet<>();
@@ -270,4 +274,9 @@
         }
 
+        if (selRow >= 0 && selRow < getRowCount()) {
+            setSelectionRow(selRow);
+            scrollRowToVisible(selRow);
+        }
+
         invalidationListeners.fireEvent(Runnable::run);
     }