Getting the exception: “Operation is not valid due to the current state of the object” when calling SPUtility.GetPrincipalsInGroup()

When calling the method:

Microsoft.SharePoint.Utilities.SPUtility.GetPrincipalsInGroup(SPWeb web, String input, Int32 maxCount, Boolean& reachedMaxCount) 

I get the following stack trace:

System.InvalidOperationException: Operation is not valid due to the current state of the object.
at Microsoft.SharePoint.Administration.Claims.SPClaimsAuthRoleProvider.GetUsersInRole(SPWeb web, String roleName, Int32 maxCount, Boolean& reachedMaxCount)
at Microsoft.SharePoint.Utilities.SPUtility.GetPrincipalsInGroup(SPWeb web, String input, Int32 maxCount, Boolean& reachedMaxCount)

This particular code is running remotely at a customer site, so I am unable to attach a debugger. This works locally and in staging outside of the customer’s site. The local site, staging and the customer’s production environment all use Claims-Based-Authentication and Windows Authentication.

Any ideas as to what could cause this exception?