Check to make sure your Caller ID number is not the same as the number you are attempting to test call.
If so, the carrier is probably not allowing you to complete the call.
To fix this:
You can change the Caller ID number, log out and back in then try the test call again and it should work. 

Check the number you are trying to dial to make sure it is a working number.

If it still doesn't place the test call then please call our office for more assistance.