Sounds like one of the employees names is incorrect. It could be something as simple as putting 'Chris' instead of 'Christopher' or 'Tony' instead of 'Anthony'.
But what if some is is actually called Chris and not Christopher, how would you get round that one? I had one of these on a payroll I do and I actually asked the person concerned was that the shortened version and they said no that was there actual name. As it was it went through fine on 12 Pay.
This is a result of trying to file an EAS (employer alignment submission) using 2012/13 rules, which HMRC won't accept any more.
If using something other than 12Pay then consult your supplier for the best way forward
If using 12Pay you probably don't even need an EAS. Everything necessary will go with your first FPS when you advance your payroll to week 2 or month 2.
Please download the latest release of our software (Help/ Get Latest Release) as it will allow you to delete the EAS(with a delete button on the form) next time you start the company up.