diff --git a/bacnet-stack/demo/handler/h_rpm_a.c b/bacnet-stack/demo/handler/h_rpm_a.c
index b30932df..dc742454 100644
--- a/bacnet-stack/demo/handler/h_rpm_a.c
+++ b/bacnet-stack/demo/handler/h_rpm_a.c
@@ -51,12 +51,14 @@ static int rpm_ack_decode_service_request(
 {
     int decoded_len = 0;        /* return value */
     int len = 0;        /* number of bytes returned from decoding */
+    uint8_t tag_number = 0; /* decoded tag number */
+    uint32_t len_value = 0; /* decoded length value */
     BACNET_READ_ACCESS_DATA *rpm_object;
     BACNET_READ_ACCESS_DATA *old_rpm_object;
     BACNET_PROPERTY_REFERENCE *rpm_property;
     BACNET_PROPERTY_REFERENCE *old_rpm_property;
     BACNET_APPLICATION_DATA_VALUE *value;
-    BACNET_APPLICATION_DATA_VALUE *old_value;
+    BACNET_APPLICATION_DATA_VALUE *old_value;
 
     rpm_object = read_access_data;
     old_rpm_object = rpm_object;
@@ -88,10 +90,11 @@ static int rpm_ack_decode_service_request(
             decoded_len += len;
             apdu_len -= len;
             apdu += len;
-            if (apdu_len && decode_is_opening_tag_number(apdu, 4)) {
+            if (apdu_len && decode_is_opening_tag_number(apdu, 4)) {
+                /* propertyValue */
                 decoded_len++;
                 apdu_len--;
-                apdu++;
+                apdu++;
                 /* note: if this is an array, there will be
                    more than one element to decode */
                 value = calloc(1, sizeof(BACNET_APPLICATION_DATA_VALUE));
@@ -99,7 +102,7 @@ static int rpm_ack_decode_service_request(
                 old_value = value;
                 while (value && (apdu_len > 0)) {
                     len =
-                        bacapp_decode_application_data(apdu, apdu_len, value);
+                        bacapp_decode_application_data(apdu, apdu_len, value);
                     decoded_len += len;
                     apdu_len -= len;
                     apdu += len;
@@ -115,7 +118,42 @@ static int rpm_ack_decode_service_request(
                         old_value->next = value;
                     }
                 }
-            }
+            } else if (apdu_len && decode_is_opening_tag_number(apdu, 5)) {
+                /* propertyAccessError */
+                decoded_len++;
+                apdu_len--;
+                apdu++;
+                /* decode the class and code sequence */
+                len =
+                    decode_tag_number_and_value(apdu, &tag_number,
+                    &len_value);
+                decoded_len += len;
+                apdu_len -= len;
+                apdu += len;
+                /* FIXME: we could validate that the tag is enumerated... */
+                len = decode_enumerated(apdu, len_value, 
+                    (int *)&rpm_property->error.error_class);
+                decoded_len += len;
+                apdu_len -= len;
+                apdu += len;
+                len =
+                    decode_tag_number_and_value(apdu, &tag_number,
+                    &len_value);
+                decoded_len += len;
+                apdu_len -= len;
+                apdu += len;
+                /* FIXME: we could validate that the tag is enumerated... */
+                len = decode_enumerated(apdu, len_value, 
+                    (int *)&rpm_property->error.error_code);
+                decoded_len += len;
+                apdu_len -= len;
+                apdu += len;
+                if (apdu_len && decode_is_closing_tag_number(apdu, 5)) {
+                    decoded_len++;
+                    apdu_len--;
+                    apdu++;
+                }
+            }
             old_rpm_property = rpm_property;
             rpm_property = calloc(1, sizeof(BACNET_PROPERTY_REFERENCE));
             old_rpm_property->next = rpm_property;
@@ -162,31 +200,42 @@ static void PrintReadPropertyMultipleData(
                 fprintf(stdout, "[%d]", listOfProperties->propertyArrayIndex);
 #endif
             }
-            value = listOfProperties->value;
-#if PRINT_ENABLED
-            if (value->next) {
-                fprintf(stdout, "{");
-                array_value = true;
-            } else {
-                array_value = false;
-            }
-#endif
-            while (value) {
-                bacapp_print_value(stdout, value,
-                    listOfProperties->propertyIdentifier);
+            value = listOfProperties->value;
+            if (value) {
 #if PRINT_ENABLED
                 if (value->next) {
-                    fprintf(stdout, ",\r\n        ");
+                    fprintf(stdout, "{");
+                    array_value = true;
                 } else {
-                    if (array_value) {
-                        fprintf(stdout, "}\r\n");
-                    } else {
-                        fprintf(stdout, "\r\n");
-                    }
+                    array_value = false;
                 }
 #endif
-                value = value->next;
-            }
+                while (value) {
+                    bacapp_print_value(stdout, value,
+                        listOfProperties->propertyIdentifier);
+#if PRINT_ENABLED
+                    if (value->next) {
+                        fprintf(stdout, ",\r\n        ");
+                    } else {
+                        if (array_value) {
+                            fprintf(stdout, "}\r\n");
+                        } else {
+                            fprintf(stdout, "\r\n");
+                        }
+                    }
+#endif
+                    value = value->next;
+                }
+            } else {
+#if PRINT_ENABLED
+                /* AccessError */
+                fprintf(stdout, "BACnet Error: %s: %s\r\n",
+                    bactext_error_class_name(
+                        (int)listOfProperties->error.error_class),
+                    bactext_error_code_name(
+                        (int)listOfProperties->error.error_code));
+#endif
+            }
             listOfProperties = listOfProperties->next;
         }
 #if PRINT_ENABLED
diff --git a/bacnet-stack/include/bacapp.h b/bacnet-stack/include/bacapp.h
index a34c2922..4f9ccc32 100644
--- a/bacnet-stack/include/bacapp.h
+++ b/bacnet-stack/include/bacapp.h
@@ -89,11 +89,20 @@ typedef struct BACnet_Application_Data_Value {
     struct BACnet_Application_Data_Value *next;
 } BACNET_APPLICATION_DATA_VALUE;
 
+struct BACnet_Access_Error;
+typedef struct BACnet_Access_Error {
+    BACNET_ERROR_CLASS error_class;
+    BACNET_ERROR_CODE error_code;
+} BACNET_ACCESS_ERROR;
+
 struct BACnet_Property_Reference;
 typedef struct BACnet_Property_Reference {
     BACNET_PROPERTY_ID propertyIdentifier;
     int32_t propertyArrayIndex; /* optional */
+    /* either value or error, but not both. 
+    Use NULL value to indicate error */
     BACNET_APPLICATION_DATA_VALUE *value;
+    BACNET_ACCESS_ERROR error;
     /* simple linked list */
     struct BACnet_Property_Reference *next;
 } BACNET_PROPERTY_REFERENCE;