Recently we started getting following error on one of our CRM environment.
Server was unable to process request.
SecLib::CrmCheckPrivilege failed. Returned hr = -2147220960 on UserId: 6e7d3c02-b2c2-df11-a8e6-78e7d1e8d0ae and PrivilegeId: cb4b339f-2b45-447e-bdd3-0bf4bbebc294
Well this does say it security issue but still does not say which entity it is failing for..Well you can easily track this down using following query. (I.e. replace relevant privilege id as per your requirement)
select name from FilteredPrivilege
where privilegeid = 'cb4b339f-2b45-447e-bdd3-0bf4bbebc294'
As in example it shows user does not have permission to update relevant leads, we given lead update permission to relevant users and that fixed the issue!!
While looking for solution on this problem I also found few CRM Security Reports displaying all role privileges, including hidden privileges.