Index: trunk/psphot/src/psphotApResid.c
===================================================================
--- trunk/psphot/src/psphotApResid.c	(revision 8137)
+++ trunk/psphot/src/psphotApResid.c	(revision 8411)
@@ -271,5 +271,5 @@
 	psf->ApTrend  = psVectorClipFitPolynomial4D (psf->ApTrend, stats, mask, PSFTRY_MASK_ALL, apResid, dMag, xPos, yPos, r2rflux, flux);
 	if (psf->ApTrend == NULL) {
-	    psError(PSPHOT_ERR_PHOTOM, false, "constant");
+	    psError(PSPHOT_ERR_PHOTOM, false, "Failed to measure apTrend");
 	    return false;
 	}