From looking at your screen shot (your running Version 5.00) and the error message, I'd say you have obtained a neutral file generated by Version 5.10 and you're trying to create a 5.00 model ? For this to work, you'll have to edit the neutral file and manually remove any data that was added for the 5.10 release. If the model is relatively small this isn't a big deal. For large models this is quite a task to do properly.