When i click to start RTC call i get this error

�[34mI20190219-11:57:44.894(1) Exception while invoking method 'stream-notify-room-users' TypeError: this.notifyUser is not a function at subscriptions.forEach.subscription (packages/rocketchat:notifications/server/lib/Notifications.js:77:50) at Array.forEach () at MethodInvocation. (packages/rocketchat:notifications/server/lib/Notifications.js:77:19) at Streamer.isWriteAllowed (packages/rocketchat:streamer/server/server.js:217:38) at MethodInvocation.method.(anonymous function) (packages/rocketchat:streamer/server/server.js:349:15) at MethodInvocation.methodMap.(anonymous function) (packages/rocketchat_monitoring.js:2731:30) at maybeAuditArgumentChecks (packages/ddp-server/livedata_server.js:1767:12) at DDP._CurrentMethodInvocation.withValue (packages/ddp-server/livedata_server.js:719:19) at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1304:12) at DDPServer._CurrentWriteFence.withValue (packages/ddp-server/livedata_server.js:717:46) at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1304:12) at Promise (packages/ddp-server/livedata_server.js:715:46) at new Promise () at Session.method (packages/ddp-server/livedata_server.js:689:23) at packages/ddp-server/livedata_server.js:559:43

it dosn't open video call

Server Setup Information:

• Version of Rocket.Chat Server: 0.74.2
• Operating System: debian 4.4.0-141-generic
• Deployment Method: standalone
• Number of Running Instances: 1
• DB Replicaset Oplog: 137
• NodeJS Version: v8.12.0
• MongoDB Version: