The RPC-COUNTCALLS test suite tries to connect to \pipe\efs.
Windows doesn't listen on that pipe, nor its it mentioned in WSPP or MCPP documentation.
However, [MS-EFSR] states that the server should listen on \pipe\efsrpc, so I assume that it was meant to test \pipe\efs.
Unless it was meant to test server response to a nonexistant pipe (like the test of \pipe\ICoffeeMachine), this test should be fixed to connect to \pipe\efsrpc instead of \pipe\efs.
The test was disabled in commit
with this comment:
s4-selftest: disable RPC-COUNTCALLS
The RPC-COUNTCALLS was useful when we were working out IDL by hand
and I find no mention of pipe\efs in any case. Let's close it.