SQL Server 2012 denies a granted permission, then can't resolve username -

i have strange behavior going on here.

we have table set up, "person", trigger inserts difference actions "person_history". can tell, when execute myself, goes well. when run this:

execute user = 'domain\user'; insert "person_history" values (...); revert; 

the first time, permission error:

msg 297, level 16, state 1, line 1
user not have permission perform action.

the second time run (after tracing permissions , finding should allowed), this:

msg 15406, level 16, state 1, line 1
cannot execute server principal because principal "domain\user" not exist, type of principal cannot impersonated, or not have permission.

it should noted first error user sees, , reported, , expect behavior not change after first run of statement.

so might missing here? i've never seen behavior before.

update: turns out insert not problem, acquiring transaction id sys.dm_tran_current_transaction problem. when statement failed (for lack of view server state permission), revert never run, , user not granted impersonate, why message changed - still executing other user.

there difference in grants between , user. need double check complete list (including roles).

impersonating user handled grants. run see grants are...

select * sys.server_principals