Cannot install network profile on Yosemite

I'm having trouble connecting to the "Eduroam" network at my University.

Some time ago the Airport connector on my motherboard decided it was time to melt down, so I'm forced to use an USB WiFi dongle (a D-Link DWA-121). However, the Wireless Network Utility (managing the new WiFi device) does not allow me to enter my username in order to connect to the network, which requires the use of 802.1x authentication protocol.

I downloaded a profile configuration file from the network configuration help page on the website but I'm not able to install it. After asking for my username and password it complains that

The 'Wi-Fi Network' payload could not be installed. The Wi-Fi network either could not be found, or could not be connected. You may need to try to reconnect at a later time.

I can only assume that the profile manager is trying to find the network using the standard Airport card on my Mac (which however will never work again until I change my motherboard) because the network is there and is shown in the Wireless Network Utility.

Is there any way to force the profile manager to install the given profile, so that I can connect to the network? Or is there any other way around this problem?

Thanks in advance for any help.