All was working find, then I tried to RSVP for a dinner I didn't create and get this error

Microsoft JScript runtime error: 'Sys.Mvc.AsyncHyperlink' is null or not an object

Any one know why this is the case.

Made this change and it seem to have done the trick

from
<script src="/Scripts/MicrosoftAjax.js" type="text/javascript" />
<script src="/Scripts/MicrosoftMvcAjax.js" type="text/javascript"/>

to
<script src="/Scripts/MicrosoftAjax.js" type="text/javascript"></script>
<script src="/Scripts/MicrosoftMvcAjax.js" type="text/javascript"></script>