vShiled endpoint license not valid

Hi all, this is my first post ...

I hava a question and i hope someone solved a similar problem. I think the solution is simple but I can't figure it out.

I've implemented a small test environment:

1 host with ESXi 4.1

1 VM windows 2003 std

1 VM Win2008r2

1 vShield manager virtual appliance 4.1

1 Deep Security Virtual appliance (turned off for the moment)

The target is testing Trend Micro deep security before implementing in production servers and verify impact in a running structure.

I installed on the Win2008 machine vsphere client, vcenter, and successfully registered vshield plugin but in the vshield tab --> endpoint status  I can only see that it is disabled because no license is present.

Well, I already have the licenses that will be used in the production environment but when i try to assign it in configuration tab --> Licensed Features --> edit --> enter key i receive the error "Invalid license key: License file not found".

Does anyone had/solved a similar problem?

Thanks to all in advance.