Hello,
I received this error during a conference call:
bridge_softmix.c:669 sfu_topologies_on_join: IAX2/ion-10687: Couldn't request topology change
The call continued and all seemed OK. Is this something to worry about?
Regards,
Ian
What version of Asterisk are you using? And no, this is fine.
Thanks - I won’t worry about it then! 
18.1.0
Regards,
Ian