SharePoint 2013 log in issue with Microsoft Live account

Hi there,

I have an associate trying to log in to our SharePoint 2013 site using his Windows live ID. He cannot gain entry to any of the sites we have shared with him. Below is the additional information he receives when trying to sign in:

Correlation ID:570c769c-bb4e-50f0-ec28-6c94d337777d

Date and Time:20/02/2014 01:20:28

URL:

User:

Issue Type:User not in directory.

Any suggestions on how to fix this?

Thanks

Zak