I'm not a Symantec expert but the following is what I believe to be true.
First there is a difference between a serial number and a license key. The serial number is used to activate the product (https://licensing.symantec.com). Once activated Symantec sends you the license key. The licence key is used to install the product/software. If a license key is not provided then the evaluation version installs instead. Evaluation version expires in 60 days.
There will be a license key for the media server (ex: BE 12 for Windows Servers) and a license key for the Agent/Option (RAWS) (ex: BEWS 12 Agent for Windows Systems). Advanced Open File Option(AOFO) is part of the 'BEWS 12 Agent for Windows Systems' license key. There isn't a separate license key for AOFO.
To help confirm that AOFO is really installed look for the file vsp.sys at <systemroot>\system32\drivers.
It might be one of those situations were you have to re-install the agents by doing the following:Uninstall the "Remote Agent" & "AOFO", Reboot the server, Reinstall the remote agent & AOFO and Reboot the server again.
I hope at least some of the above helps.