Add some small annotation to runtime error. Most likely reason is 'doublePrecision' setting

python/_cosmotool.pyx

@@ -538,9 +538,12 @@ def loadRamses(str basepath, int snapshot_id, int cpu_id, bool doublePrecision =
   if loadId:
      flags |= NEED_GADGET_ID
 
+  try:
     data = loadRamsesSimu(basepath, snapshot_id, cpu_id, doublePrecision, flags)
     if data == <SimuData*>0:
       return None
+  except RuntimeError as e:
+    raise RuntimeError(e.message + ' (check the float precision in snapshot)')
 
   return PySimulationAdaptor(wrap_simudata(data, flags))