In case you violated one of Rules of the Streaming Policy , your live-streaming feature has been either, temporarily or permanently disabled. When the live streams are disabled, you can neither start streaming yourself nor join streams of other users. 

In case the live streams have been temporarily disabled, you have to wait until the time is up (the app has a countdown until the feature is active again).

In case the live streams have been disabled permanently, unfortunately, you will not be able to live stream or join other streams anymore.

Should you think this happened by mistake, feel free to contact Taimi Live Help. 

More information about the reasons for disabling  the Live Stream feature can be found here:  Streaming policy.