Index: trunk/ppStack/src/ppStackReadout.c
===================================================================
--- trunk/ppStack/src/ppStackReadout.c	(revision 14298)
+++ trunk/ppStack/src/ppStackReadout.c	(revision 14300)
@@ -193,4 +193,7 @@
             return false;
         }
+        if (!outHDU->header) {
+            outHDU->header = psMetadataAlloc();
+        }
         if (!pmAstromWriteWCS(outHDU->header, outFPA, outCell->parent, WCS_TOLERANCE)) {
             psError(PS_ERR_UNKNOWN, false, "Unable to write WCS astrometry to output FPA.");