These arguments should be binary instead of strings, otherwise it won't work properly

src/mod_admin_extra.erl

@@ -418,12 +418,12 @@ commands() ->
      #ejabberd_commands{name = push_roster, tags = [roster],
 			desc = "Push template roster from file to a user",
 			module = ?MODULE, function = push_roster,
-			args = [{file, string}, {user, string}, {host, string}],
+			args = [{file, binary}, {user, binary}, {host, binary}],
 			result = {res, rescode}},
      #ejabberd_commands{name = push_roster_all, tags = [roster],
 			desc = "Push template roster from file to all those users",
 			module = ?MODULE, function = push_roster_all,
-			args = [{file, string}],
+			args = [{file, binary}],
 			result = {res, rescode}},
      #ejabberd_commands{name = push_alltoall, tags = [roster],
 			desc = "Add all the users to all the users of Host in Group",