[Gandolf]

I am installing a 3CX with a Grandstream FXO GXW4108, i have followed instructions on the 3CX site.
I can make outside calls, but i cannot receive calls.
I get error message
Reason: Credentials don't match, check that authorization-ID and password match the ones in extension settings
3CX version is 9 and Grandstream FXO is 1.3.4.9
I copy from the 3Cx the authorization id and password , but i still have the same problem.

[leejor]

I copy from the 3Cx the authorization id and password , but i still have the same problem.

Are you "cutting and pasting"? Sometimes that includes some unseen spaces that should not be in there.