Freeconferencecall bridge

Hi

I am having issues incorporating the audio conference call details from freeconferencecall.com (it is a toll number). Whenever I test the audio connection, I am getting the following error

"

Connecting to server...

Requesting connection to Audio Bridge...

Dialing into the conference...

A configuration error occurred. Please verify the audio settings for this meeting in Adobe Connect Central.

Disconnected from the Audio Bridge.

"

Can you please assist with this. I need to have an option for free or cheap audio conferencing. Thank you very much!