VAS mod_auth_vas error failed with result = 983040, any help?

Hi,
trying kerberose login from internet explorer and got below mod_auth_vas error.
any thoughts?
[mod_auth_vas] do_gss_spnego_accept: VAS_ERR_INTERNAL: First call to gss_accept_sec_context() failed, minor_status = 0, result = 983040,


thanks