Error (Couldn't bring up network: failed to find plugin "rancher-bridge"

UPDATE

I upgraded to v1.5.5 and the same network messages came back. Downgrading to v1.5.2 solved the problem.

Aaand I spoke too soon. Cannot get any additional containers to come up on any machine in my cluster. Even tried a simple container busybox. These messages are constant in the network-manager logs:

4/18/2017 2:36:09 PMtime="2017-04-18T18:36:09Z" level=info msg="Setting up binaries for: map[rancher-bridge:9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302]"
4/18/2017 2:36:09 PMtime="2017-04-18T18:36:09Z" level=error msg="Failed to apply cni conf: Error: No such container: 9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302"
4/18/2017 2:36:13 PMtime="2017-04-18T18:36:13Z" level=info msg="Setting up binaries for: map[rancher-bridge:9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302]"
4/18/2017 2:36:13 PMtime="2017-04-18T18:36:13Z" level=error msg="Failed to apply cni conf: Error: No such container: 9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302"
4/18/2017 2:38:35 PMtime="2017-04-18T18:38:35Z" level=info msg="Setting up binaries for: map[rancher-bridge:9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302]"
4/18/2017 2:38:35 PMtime="2017-04-18T18:38:35Z" level=error msg="Failed to apply cni conf: Error: No such container: 9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302"
4/18/2017 2:38:49 PMtime="2017-04-18T18:38:49Z" level=info msg="Setting up binaries for: map[rancher-bridge:9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302]"
4/18/2017 2:38:49 PMtime="2017-04-18T18:38:49Z" level=error msg="Failed to apply cni conf: Error: No such container: 9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302"
4/18/2017 2:41:57 PMnet.ipv4.conf.docker0.route_localnet = 1
4/18/2017 2:41:57 PMtime="2017-04-18T18:41:57Z" level=info msg="Setting up binaries for: map[rancher-bridge:9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302]"
4/18/2017 2:41:57 PMtime="2017-04-18T18:41:57Z" level=error msg="Failed to apply cni conf: Error: No such container: 9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302"
4/18/2017 2:43:38 PMtime="2017-04-18T18:43:38Z" level=info msg="Setting up binaries for: map[rancher-bridge:9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302]"
4/18/2017 2:43:38 PMtime="2017-04-18T18:43:38Z" level=error msg="Failed to apply cni conf: Error: No such container: 9038e3e361bcdc5c98cea8f12e38435365c7624da7c28018e6c2300f9770d302"

who can help me