--- a/java/org/apache/tomcat/util/digester/Digester.java	
+++ a/java/org/apache/tomcat/util/digester/Digester.java	
@@ -1989,6 +1989,7 @@ public class Digester extends DefaultHandler2 {
                 }
             } catch (Exception e) {
                 // ignore - let the attribute have its original value
+                log.warn("Attribute [" + newAttrs.getLocalName(i) + "] failed to update and remains [" + value + "].", e);
             }
         }