Index: trunk/ppStack/src/ppStackLoop.c
===================================================================
--- trunk/ppStack/src/ppStackLoop.c	(revision 18508)
+++ trunk/ppStack/src/ppStackLoop.c	(revision 18591)
@@ -204,5 +204,4 @@
 
     bool mdok;                          // Status of MD lookup
-    psMaskType maskBlank = psMetadataLookupU8(NULL, config->arguments, "MASK.BLANK"); // Mask for blank reg.
     bool tempDelete = psMetadataLookupBool(&mdok, config->arguments, "TEMP.DELETE"); // Delete temporary files?
     const char *tempImage = psMetadataLookupStr(NULL, config->arguments, "TEMP.IMAGE"); // Suffix for temporary images
@@ -242,4 +241,9 @@
     psMetadata *ppsub = psMetadataLookupMetadata(NULL, config->recipes, "PPSUB"); // PPSUB recipe
     int overlap = 2 * psMetadataLookupS32(NULL, ppsub, "KERNEL.SIZE"); // Overlap by kernel size between consecutive scans
+
+    if (!pmConfigMaskSetBits(NULL, NULL, config)) {
+        psError(PS_ERR_UNKNOWN, false, "Unable to determine mask value.");
+        return false;
+    }
 
     memDump("start");
@@ -790,5 +794,5 @@
         if (stats) {
             psTrace("ppStack", 1, "Gathering statistics on stacked image....\n");
-            ppStatsFPA(stats, outCell->parent->parent, view, maskBlank, config);
+            ppStatsFPA(stats, outCell->parent->parent, view, pmConfigMaskGet("BLANK", config), config);
         }