if the game has no region named Muschelplateau, then ignore this code

scripts/eressea/embassy.lua

@@ -26,6 +26,9 @@ end
 
 function embassy.update()
     -- Muschelplateau
+    if home==nil then
+        return
+    end
     eressea.log.debug("updating embassies in " .. tostring(home))
     local u
     for u in home.units do