Great to hear that Suess.
How did you solve it?
Did you create the enhancement point in se24 t-code?
If that's the case, please mark the answer as correct so it can help other pepople that has the same problem as you.
Regarding the error you are getting: "User or password is incorrect for target system." I think is related with the password in the backend system.
In case you are using a central hub architecture for the SAP Netweaver gateway, you have to define the same user and password in the Backend/Gateway systems.
Anyway, this topic should be discussed in a new thread.
Regards,
Emanuel