RADIUSdesk allows you to conveniently select items out of the dictionary files to formulate profiles or to manage attributes belonging to users (Permanent Users, Vouchers, Devices)
In order for the Select control to work as intended ensure that the Nginx webserver can read the /etc/freeradius/3.0/dictionary file.
sudo chown freerad:www-data /etc/freeradius
sudo chown freerad:www-data /etc/freeradius/3.0
sudo chown freerad:www-data /etc/freeradius/3.0/dictionary
sudo mkdir /etc/freeradius/3.0/dictionary_overrides
VENDOR Accel-PPP 55999
BEGIN-VENDOR Accel-PPP
ATTRIBUTE Accel-VRF-Name 1 string
END-VENDOR Accel-PPP
#This is not required for FreeRADIUS3 anymore but it is required for RADIUSdesk
$INCLUDE /usr/share/freeradius/dictionary
$INCLUDE /etc/freeradius/3.0/dictionary_overrides/dictionary.accel
sudo service freeradius restart