Can't join domain

I am trying to add a computer (windows 8.1) to a windows 2012R2 domain with the "Update configuration"-task, but i'm getting an error.

In the Modify Configuration prompt i've filled:

• Domain (lan.domain.xx/Workstations/Mijdrecht/Leerlingen)
• Computername: %NAME% (as token)

And under: Options > Domain accounts i've added the right account with sufficient rights to add a pc to the domain.

As error i'm seeing:

"The system cannot open the device or file specified".

With a couple of changes within this task i am able to do the following:

• Change PC name
• Change Workgroup

Anyone got an idea what to do?

Ps. adding the computer manual, with the same credentials works without problems (so it isn't a bad password..)

Thanks in advance,

Jorrit