Vivox: What causes status code 20000 ("XMPP unknown error")?

Symptoms:

The Vivox SDK status code 20000 ("XMPP unknown error") can occur in two different scenarios when failing to successfully mute a user.

Vivox Core SDK only: 20000 can also occur when issuing an add_session request using a channel URI with a domain that does not match the one you're connected too.

Cause:

Status code 20000 will occur if one of the following conditions is true when the mute request is processed:

• In all Vivox SDKs: The channel participant target of the mute operation is no longer in the channel.
• In Unity/Unreal SDK: You tried to mute a user in a text-only channel.
• In Core SDK: You tried to mute a user in a text-only channel using a vx_mute_scope other than mute_scope_text.

Vivox Core SDK only: Let's say you sign in user sip:.blindmelon-AppName-dev.jerky.@tla.vivox.com, then try to connect them to voice channel sip:confctl-g-blindmelon-AppName-dev.testchannel@qat.vivox.com. The vx_req_sessiongroup_add_session request will fail with 20000 because of the mismatched domains.

Resolution:

• In all Vivox SDKs: When connected to channel for audio (or audio + text), your application should treat status code 20000 resulting from a channel participant mute request as a success: the target user is no longer in the channel, so their mute status is no longer relevant.
• In Unity/Unreal SDK: Muting users in a text-only channel is not possible.
• In Core SDK: When muting a user in a text-only channel, ensure you set the request field vx_mute_scope scope to a value of mute_scope_text.

Vivox Core SDK only: Users connected to one Vivox domain cannot join a channel hosted on another domain. Cases where this is attempted are typically accidental, resulting from a typo or incorrect variable usage.