The problem could be solved by deleting the tcweb2_user_prefs.json so that VuGen can correctly recreate it.
Please follow the steps below:
Go to the %AppData%\Hewlett-Packard\TruClient
for example the folder could be: C:\Users\CurrentUser\AppData\Roaming\Hewlett-Packard\TruClient
Make a backup copy of tcweb2_user_prefs.json
Open a TruClient Firefox script and VuGen will correctly recreate it.