Hi trying to send DTMF as conference admin for invite some external number to conference.
DTMF sends by programm.
When dtmf sends i see this error

[ERR] switch_ivr_async  dmachine overflow error!

And then dialplan not works for call this number.

I see all INFOs with needed digits but after each info (read after each digit) i see this error

it looks like i sending INFO's too fast. 

Anyone had this issue before and may be resolved it?