Problem running post install script

I have installed DS-5 v5.28.0 on Ubuntu 16.04 LTS.

The post install stage reported the following problem:

Post install stage provides the following functions:
- Installation of USB drivers for RealView ICE and DSTREAM hardware units
- Set default toolkit selection

Please answer with one of: 'yes/y' or 'no/n'
Run post install setup scripts? [default: yes] yes

--- Running post install setup scripts

No default toolkit set

As far as I can tell, the USB drivers for DStream have not been installed.

How do I set the default toolkit to enable the post install setup to complete successfully?

Thanks.