Index: trunk/psModules/src/imcombine/pmPSFEnvelope.c
===================================================================
--- trunk/psModules/src/imcombine/pmPSFEnvelope.c	(revision 19794)
+++ trunk/psModules/src/imcombine/pmPSFEnvelope.c	(revision 19998)
@@ -146,4 +146,5 @@
             // Get the radius
             pmModel *model = pmModelFromPSFforXY(psf, x, y, PEAK_FLUX); // Model for source
+	    psAssert (model, "failed to generate model: should this be an error or not?");
             float srcRadius = model->modelRadius(model->params, PS_SQR(WEIGHT_VAL)); // Radius for source
             if (srcRadius > maxRadius) {
@@ -296,4 +297,5 @@
         pmModel *fakeModel = pmModelFromPSFforXY(psf, (float)numCols / 2.0, (float)numRows / 2.0,
                                                  1.0); // Fake model, with central intensity of 1.0
+	psAssert (fakeModel, "failed to generate model: should this be an error or not?");
         float flux0 = fakeModel->modelFlux(fakeModel->params); // Flux for central intensity of 1.0
         for (int i = 0; i < numFakes; i++) {