Index: binaries/data/mods/public/gui/structree/load.js
===================================================================
--- binaries/data/mods/public/gui/structree/load.js
+++ binaries/data/mods/public/gui/structree/load.js
@@ -16,7 +16,7 @@
 			{
 				build = build.replace("{civ}", g_SelectedCiv);
 				unit.production.units.push(build);
-				if (g_Lists.units.indexOf(build) < 0)
+				if (Engine.TemplateExists(build) && g_Lists.units.indexOf(build) < 0)
 					g_Lists.units.push(build);
 			}
 		}
@@ -36,7 +36,7 @@
 		for (let build of template.Builder.Entities._string.split(" "))
 		{
 			build = build.replace("{civ}", g_SelectedCiv);
-			if (g_Lists.structures.indexOf(build) < 0)
+			if (Engine.TemplateExists(build) && g_Lists.structures.indexOf(build) < 0)
 				g_Lists.structures.push(build);
 		}
 
@@ -63,7 +63,7 @@
 			{
 				build = build.replace("{civ}", g_SelectedCiv);
 				structure.production.units.push(build);
-				if (g_Lists.units.indexOf(build) < 0)
+				if (Engine.TemplateExists(build) && g_Lists.units.indexOf(build) < 0)
 					g_Lists.units.push(build);
 			}
 
@@ -166,7 +166,7 @@
 }
 
 /**
- * Loads the names of all phases required to research the given technologies.
+ * Determine order of phases.
  *
  * @param techs The current available store of techs
  *
@@ -210,6 +210,10 @@
 			phaseList.splice(reqPhasePos+1, 0, myPhase);
 			phaseList.splice(myPhasePos, 1);
 		}
+		else if (reqPhasePos < 0 && myPhasePos < 0)
+			// If neither phase is in the list, then add them both to the end and
+			// rely on later iterations relocating them to their correct place.
+			phaseList.push(reqPhase, myPhase);
 	}
 
 	return phaseList;