After version 4.3 Alpha 6, I also started receiving log errors as follows.
Line 2: [I] Nov 18 14:47:17 ndnproxy: [7464] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 25: [I] Nov 18 15:11:42 ndnproxy: [3AD6] answer from wrong socket (got from 34 127.0.0.1:40500 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40500 to 49615).
Line 33: [I] Nov 18 15:16:59 ndnproxy: [DEED] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 34: [I] Nov 18 15:17:14 ndnproxy: [2908] answer from wrong socket (got from 34 127.0.0.1:40501 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40501 to 49615).
Line 35: [I] Nov 18 15:18:29 ndnproxy: [DB9D] answer from wrong socket (got from 34 127.0.0.1:40501 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40501 to 49615).
Line 36: [I] Nov 18 15:18:30 ndnproxy: [C563] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 37: [I] Nov 18 15:18:31 ndnproxy: [103D] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 57: [I] Nov 18 15:24:48 ndnproxy: [51DF] answer from wrong socket (got from 34 127.0.0.1:40501 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40501 to 49615).
Line 73: [I] Nov 18 15:27:11 ndnproxy: [DD0A] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 79: [I] Nov 18 15:29:39 ndnproxy: [0FD0] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 90: [I] Nov 18 15:34:09 ndnproxy: [C5E3] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 91: [I] Nov 18 15:34:09 ndnproxy: [318D] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 92: [I] Nov 18 15:34:11 ndnproxy: [1377] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 94: [I] Nov 18 15:37:39 ndnproxy: [EC3A] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 95: [I] Nov 18 15:38:44 ndnproxy: [23CD] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).
Line 96: [I] Nov 18 15:40:20 ndnproxy: [5E9C] answer from wrong socket (got from 34 127.0.0.1:40508 [0] to 127.0.0.1:0, exp from 33 127.0.0.1:40508 to 49615).