There may be an easier way to resolve this, but in case anybody else has this problem also the following is what worked for me:
- If 'base_model_harnessInfo.xml' is missing, create a dummy test harness and build it, which will generate the xml file
- open the harnessInfo.xml and take note of the HarnessUUID field in the Harness section
- Copy the Harness section and past it as a new Harness section within the same xml file. so the format will roughly be
<HarnessInformation>
<Harness>
...
</Harness>
<Harness>
...
</Harness>
</HarnessInformation>
4. In the Matlab command window type the following : get_param('YOURHARNESSNAME','HarnessUUID')
5. The result should take the format of the UUID noted in step 2
6. Copy/Paste that HarnessUUID into the respective field of the new <Harness> ... </Harness>