rknn_init, recv(MsgLoadAck) fail, -9(ERROR_PIPE) != 368!

My platform has the same issue sometimes. It doesn't happen all the time.
Below is the printout during the run:

D RKNNAPI: ==============================================
D RKNNAPI: RKNN VERSION:
D RKNNAPI:   API: 1.2.0 (db63ace build: 2019-09-17 14:23:41)
D RKNNAPI:   DRV: 0.91 (237fb1a build: 2018-12-29 16:46:59)
D RKNNAPI: ==============================================

Is DRV-version 0.91 too old? How do I update new DRV?