Hi Johan,
It seems you have used Non Royalty (Non Video) serial no to create Premiere Pro CC Package. Please use Video Serial to activate Premiere Pro CC and then you will get all the required codecs.
Please login to http://licensing.adobe.com and get the Video serial no for activating Premiere pro CC.
Once you get it then please use Adobe Provisioning Tool Enterprise Edition (APTEE) to create a Licensing file and then execute the same on the impacted computer.
You can refer to this link for APTEE.
Creative Cloud Help | Using Adobe Provisioning Toolkit Enterprise Edition
Hope it helps.
Regards,
Abhijit