Agent Clients status are down. MID Server agent logs show "ERROR in webserver API Key authenticator: unauthorized request: invalid api key"Issue All Agent Client status is down. Mid Server agent logs shows the following errors: com.service_now.mid.webserver.jetty.ApiKeyAuthenticator - ERROR in webserver API Key authenticator: unauthorized request: invalid api key If you enabled MID Server debug you will see the Agent Client HTTP request header as below: 07/19/21 20:09:18 (254) qtp123456789-185 DEBUG: (185) com.service_now.mid.webserver.jetty.WebServer - REQUEST for //11.12.13.14:8081/ws/events on HttpChannelOverHttp@5dfd111g{s=HttpChannelState@8584bb31{s=IDLE rs=BLOCKING os=OPEN is=IDLE awp=false se=false i=true al=0},r=1,c=false/false,a=IDLE,uri=//11.12.13.14:8081/ws/events,age=0} GET //11.12.13.14:8081/ws/events HTTP/1.1 Host: 11.12.13.14:8081 User-Agent: Go-http-client/1.1 Accept: application/octet-stream Authorization: Key abc123defxyx00012346gg Connection: Upgrade Content-Type: application/json Sec-WebSocket-Key: B36Pf7pYmh02nK5NGfcjNg== Sec-WebSocket-Version: 13 Sensu-Agentname: MRS1SWLTCOR01 Sensu-Namespace: default Sensu-Subscriptions: Upgrade: websocket ReleaseAll current supported release with Agent Client Collector installed.CauseAgent Clients uses the MID Web Server API key as part of the header when sending data to the MID Server Web Server. This API Key is configured in the YML configuration file. If a new API Key is generated for the MID Web Server, then this new key needs to be set as well in the YML file of each Agent Clients. Generation of new API Key is done via MID Web Server API key module. To retrieve the API Key, please navigate to MID Web Server > MID Web Server API Key. In the debug log above the Authorization: Key must match what you currently have in the instance.ResolutionModify the "api-key" in the YML file as below: Locate the YML file in the agent client configuration folder for each host. The file location is dependent on the operating system. For Windows OS it is "C:\ProgramData\ServiceNow\agent-client-collector\config\acc.yml" for Linux "/etc/servicenow/agent-client-collector/acc.yml"Open the "acc.yml" file using a text editor and locate the API Key. This should be something like this "api-key: "encrypted:rpR+NabUPyLGRnW4GdNvM0I7GRv3GwTnfI4tgJApm9uK5ch0V+PzO9sJIP+6hmgL" note the encrypted values would be different as the API Key is unique to each instance.Replace the API Key encrypted value with the API Key from your instance. The new value should be set as is(un-encrypted) - "api-key: "a83820b58f723300e7e16c7827bdeed2"Please save and then restart the Agent Client Service - For Windows OS, go to the Windows Services page (services.msc from cmd) and look for the Agent Client Collector service to start/stop/restart. For Linux please enter the following "systemctl restart acc". The API Key in the YML file will be encrypted once the Agent Client successfully connects to MID Server Web Server.