InDesign Server CC 2014: How to enter serialnumber

Dear all,

We are running InDesign Server CC 2014 on a Windows Server 2008 R2 Standard (64bit).

We start InDesign.exe from the command line.

We just bought another license for 1 more year, with this we got a new serial number. But... where to enter this new serial number to activate?

Some further informations:

- In older Version of InDesign, you could provide the serial when starting InDesign in the command line (but this is obviously no longer possible in the current versions InDesign Server CC 2014. In documentation, this option doesn't appear any more.).

- We already tried the "adobe_prtk" for an offline activation, but this only returns "Return Code 14".

new serial: xxxx-xxxx-xxxx-xxxx-xxxx-xxxx

requestcode:  ABCefghijklmnopQRst...=

response/replycode: Yyyy yyyy yyyy yyyy yyyY yyyy yyyy yyyy yyyy yyyy YYY

->

adobe_prtk --tool=Type1Exception --accept --serial=xxxx-xxxx-xxxx-xxxx-xxxx-xxxx --responsecode=Yyyy yyyy yyyy yyyy yyyY yyyy yyyy yyyy yyyy yyyy YYY=  --leid=InDesignServer-10-Win-GM

-> Return Code 14

Return Code 14 is documented as "unknown error".

- I have internet access on the server

-  I checked that the GlobalSign Root CA as discribed here is active:

Solutions to sign-in, activation, and connection errors with Creative Cloud and Creative Suite applications.

Anyone knows a solution?

Thanks in advance!

Andreas