throw execp when index not found

src/camel/Class/ClassEngine.cc

@@ -72,7 +72,7 @@ ClassParams::findIndex(const string& name){
       index=i; break;
     }
   }
-  planck_assert(index>=0,string("key ")+name+ " not found in ClassParams");
+  if (index<0) throw Message_error(string("key ")+name+ " not found in ClassParams");
   return static_cast<size_t>(index);
 }