Hi,

I do see this in logs and this seems normal, cause we do store that $sht and in a case if call is cancelled or ended we do not clean that $sht until it resets in 120 seconds, so if any register arrives without call during that 120 seconds, this is what you will see. Let assume somebody calls a subscriber, then we do store transaction and  we do this "$sht(vtp=>stored::$rU) = 1", if call ends and by some reason without any other call another register arrives from subscriber with same "$tU" within 120 seconds after ($sht(vtp=>stored::$rU) = 1;), then this register will go to PUSHJOIN and we check if transaction is stored, because there is no call it is not stored and then it checks if $sht(vtp=>stored::$rU) equal to 1, because this is not resetted yet(120 seconds do not pass), ts_append tries to append branch, but there is no branch and that why you see this error.

I would like to add that for me this error seems harmless and everything works flawlessly.