diff --git a/fieldpattern.cpp b/fieldpattern.cpp
index 571a55b5..ad58f4f8 100644
--- a/fieldpattern.cpp
+++ b/fieldpattern.cpp
@@ -721,7 +721,9 @@ fpattern& getcurrfp() {
     return fp;
     }
   if(sphere || euclid) return fp_invalid;
-  return fp43;
+  if(S7 == 7 && S3 == 3)
+    return fp43;
+  return fp_invalid;
   }
 
 // extra information for field quotient extra configuration
diff --git a/graph.cpp b/graph.cpp
index 4754dd8c..84b8f39d 100644
--- a/graph.cpp
+++ b/graph.cpp
@@ -5823,7 +5823,7 @@ auto graphcm = addHook(clearmemory, 0, [] () {
 
 void resetGeometry() {
   precalc();
-  if(hyperbolic) currfp.analyze();
+  if(hyperbolic && &currfp != &fieldpattern::fp_invalid) currfp.analyze();
 #if CAP_GL
   resetGL();
 #endif
diff --git a/heptagon.cpp b/heptagon.cpp
index c316b319..60f92c43 100644
--- a/heptagon.cpp
+++ b/heptagon.cpp
@@ -74,7 +74,8 @@ heptagon *buildHeptagon(heptagon *parent, int d, hstate s, int pard = 0, int fix
     h->rval0 = h->rval1 = 0;
     h->emeraldval = emerald_heptagon(parent->emeraldval, d);
     h->zebraval = zebra_heptagon(parent->zebraval, d);
-    h->fieldval = currfp.connections[fieldpattern::btspin(parent->fieldval, d)];
+    if(&currfp != &fieldpattern::fp_invalid)
+      h->fieldval = currfp.connections[fieldpattern::btspin(parent->fieldval, d)];
     if(a38) 
       h->fiftyval = fifty_38(parent->fiftyval, d);  
     else if(parent->s == hsOrigin)
diff --git a/pattern2.cpp b/pattern2.cpp
index fd615a79..0a830f92 100644
--- a/pattern2.cpp
+++ b/pattern2.cpp
@@ -355,6 +355,7 @@ int fieldval_uniq(cell *c) {
     return gmod(p.first * torusconfig::dx + p.second * torusconfig::dy, torusconfig::qty);
     }
   else if(binarytiling || archimedean) return 0;
+  else if(&currfp == &fp_invalid) return 0;
   else if(ctof(c) || NONSTDVAR) return c->master->fieldval/S7;
   else {
     int z = 0;