[ERROR] event.WriteError: event.newError: missing error: invalid parameter

[micchickenburger]

Describe the bug

We get error [ERROR] event.WriteError: event.newError: missing error: invalid parameter on the Boundary workers when cancelling sessions in the UI.

Mar 10 16:48:12 ip-10-15-2-165 boundary[18049]: 2022-03-10T16:48:12.961Z [ERROR] event.WriteError: event.newError: missing error: invalid parameter
Mar 10 16:48:12 ip-10-15-2-165 boundary[18049]: 2022-03-10T16:48:12.961Z [ERROR] event.WriteError: unable to create new error to write error: <nil>
Mar 10 16:48:12 ip-10-15-2-165 boundary[18049]: {"id":"qRJGvP3Pw4","source":"https://hashicorp.com/boundary/us-east-2-worker-rxosqtnrrk","specversion":"1.0","type":"error","data":{"error":"failed to close WebSocket: failed to read frame header: EOF","error_fields":{},"id":"e_J4kGMpFMNu","version":"v0.1","op":"worker.(Worker).handleProxy","info":{"msg":"error closing client connection"}},"datacontentype":"application/cloudevents","time":"2022-03-10T16:48:12.963873011Z"}

To Reproduce
Steps to reproduce the behavior:

1. Under Targets tab, click Connect button on a target
2. Under Sessions tab, click Cancel on the session
3. See error in boundary worker log

Expected behavior
A clear and concise description of what you expected to happen.

Additional context
UI Version:

Boundary version running on worker:

Mar 10 15:56:52 ip-10-15-2-165 boundary[18049]:             AWS KMS Region: us-east-2
Mar 10 15:56:52 ip-10-15-2-165 boundary[18049]:                        Cgo: disabled
Mar 10 15:56:52 ip-10-15-2-165 boundary[18049]:                 Listener 1: tcp (addr: "10.15.2.165:9202", max_request_duration: "1m30s", purpose: "proxy")
Mar 10 15:56:52 ip-10-15-2-165 boundary[18049]:                  Log Level: info
Mar 10 15:56:52 ip-10-15-2-165 boundary[18049]:                      Mlock: supported: true, enabled: true
Mar 10 15:56:52 ip-10-15-2-165 boundary[18049]:                    Version: Boundary v0.7.4
Mar 10 15:56:52 ip-10-15-2-165 boundary[18049]:                Version Sha: 221acff4cc4d1f9be7619a657274c043999e62cc

[irenarindos]

@micchickenburger Thanks so much for finding this bug! We've been able to recreate it & are working on a fix.