Index: trunk/src/org/openstreetmap/josm/gui/tagging/presets/items/Text.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/tagging/presets/items/Text.java	(revision 17898)
+++ trunk/src/org/openstreetmap/josm/gui/tagging/presets/items/Text.java	(revision 17899)
@@ -22,4 +22,5 @@
 import javax.swing.JPanel;
 import javax.swing.JToggleButton;
+import javax.swing.SwingUtilities;
 
 import org.openstreetmap.josm.data.osm.Tag;
@@ -256,5 +257,7 @@
             support.addListener((source, key, newValue) -> {
                 if (source != this) {
-                    textField.setItem(valueTemplate.getText(support));
+                    String valueTemplateText = valueTemplate.getText(support);
+                    Logging.trace("Evaluating value_template {0} for key {1} => {2}", valueTemplate, key, valueTemplateText);
+                    SwingUtilities.invokeLater(() -> textField.setItem(valueTemplateText));
                 }
             });