This is normally caused by a loop in a HuntGroup setup.
the error message basically means that you have called an extension that is forwarded to an entension that is forwarded to an entension that is forwarded etc, etc. A maximum of 10 forwards is supported, after this you get the error message.
If you cannot work it out yourself forward me your config and I will do it for you.
Mar sin leat
endpoint
(when you get here there's no where else to go!)