The device and platform

Name the limit you are seeing
Vi’s FAQ distinguishes devices that can be logged in from simultaneous viewing allowed by content partners. A device list records where an account is registered. A playback limit concerns what is watching now. Those counts should not be substituted for one another.
Read the exact message on the screen that cannot start. Does it ask you to remove a registered device, or does it say too many streams are playing? Record the partner and programme as well, because a bundle can lead to more than one playback system.
Check active playback before removing devices
If the message concerns simultaneous streams, check the other screens currently playing under the relevant account. A paused programme or an app left open may be worth examining, but this guide does not claim every partner counts those states in the same way.
Stop the viewing session you no longer need through its normal controls, then try the same title again. Removing every registered device is a much broader change and can require people to sign in again without resolving the particular partner’s active-session question. Use the action that matches the message.
Compare like with like
For a useful comparison, keep the programme and partner constant while changing only the competing viewing session. If one partner works while another does not, that does not prove the bundle has one universal stream allowance. It gives you a more specific issue to raise.
Prepare a short household note listing the account, active screen and partner for the evening. Avoid circulating passwords in the note. The purpose is coordination: people can see whether the screen they need is already in use and which account should be checked.
Escalate with the evidence attached
If a limit persists after all known sessions have ended, report the message, time, partner, active pack and affected device to support. State that you have distinguished registered devices from current playback. No numerical allowance in this article overrides the current partner or plan terms.
Questions answered
Can every registered device necessarily play at once?
No. Vi says partner rules can govern concurrent playback separately.
Should I remove all devices for every stream-limit message?
First identify whether the message concerns registration or active viewing, then use the relevant official control.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.

