‘It is not allowed to send private messages to the conference’: what to do in XMPP

Mæstro · Post by **Mæstro** » 2026-02-24, 13:23

Moonchild has generously granted me permission to post this, despite its irrelevance to the UXP, for public awareness of information here which is, to my knowledge, totally unavailable elsewhere.

If a user encounters this error in Jabber, he must be kicked from the chatroom. He should not leave himself. When he rejoins manually, he should be able to speak again. In some clients, such as Conversejs, the user may not be warned, but will find his messages do not send.

In the process of migrating from Discord to XMPP, one friend joining our MUC encountered a bizarre, and apparently very rare, problem in XMPP. In any client he tried, viz Conversejs and Gajim on Windows 11, he was unable to post messages in our chatroom. This despite the fact he was able to exchange private messages and post to other MUC on third servers without difficulty, and our own ability (including a friend’s in Windows 11 on the same clients) to post there. Conversejs gave no hint of the problem, but Gajim gave a telltale sign: the titular error message.

Searching for this error online mostly gave advice for a similarly phrased error, viz ‘only occupants are allowed…’, but this advice (rejoining without leaving the server) had no effect. Searching for the exact phrase in Startpage, a Google frontend, gave just one result, a mere list of XMPP messages with Swedish translations. Manually giving him the visitor role and member affiliation, despite the fact the chatroom was unmoderated (see the specification) and he already possessed these traits, failed also. His own attempts to solve the problem by leaving and rejoining, several times, were also in vain.

Because this problem has never before been documented, and my personal website is still some weeks or months away, I offer this here as a record should anybody else suffer this problem, whether reading the message outright or simply being unable to send messages in a specific conference to which he is otherwise entitled.