Due to it only occurring in one environment I presumed it was a deployment issue. However I was incorrect.
We were receiving the above error because we restored a full database from one environment to another. We had some JavaScript which was checking the owner of a record. The owner was displayed on the record however it was from an external domain.
Because of this it threw an error right down in the CRM depths at:-
function
crmForm_window_onload_handler(eventObj,eventArgs){
try{
var
eContext=Mscrm.FormUtility.constructExecutionObject(eventObj,0,null,null);
eContext=Mscrm.FormUtility.constructExecutionObject(eventObj,0,null,eContext)
loadInsideView();
eContext=Mscrm.FormUtility.constructExecutionObject(eventObj,1,null,eContext)
CEI.Initialize();
} catch(e) {
displayError('window', 'onload', e.description);
}
}
So if you see an error occurring like this that did not appear in other environments make sure you confirm that the record you are looking at is correctly mapped to the new domain.