Problem to join GroupChat

Hi,

We are using OpenFire3.6.2 and Spark 2.5.8.

A problem is detected when a invitee is joining GroupChat.

It is occurred on a certain Spark user but not on all Spark users.

The symptom is as follows;

When an invitee tried to join a GroupChat, the message “(user name) has been joined.” is displayed on the GroupChat board.

Continuously, “(user name)2 has been joined.”, “(user name)3 has been joined.”, “(user name)4 has been joined.”,

“(user name)5 has been joined.” and so on are displayed, but the invitee cannot complete to join.

Finaly, the error messge “No response from server” appears.

Could you please let me know a resolution or a workaround for it if it is known matter.

Thank you in advance.

Best regards,

Yukari Hirota