Nuitrack license.json: cannot open file

I execute my program in Ubuntu 16.04 and after about 10 seconds I get an exception that says: LicenseNotAcquired exception (ExceptionType: 6).
The exception is evident. I must activate the license.
I run the Nuitrack activation tool using the $nuitrack command in the command line, I run the test without problems, but when I try to activate the license an error appears:

Getting a 3D sensor list…
3D sensor list was updated
Starting test…
3D serial sensor number: 18112230005
3D sensor provider name: OpenNI2DepthProvider
Test completed!
Activation error: NuitrackException: /usr/etc/nuitrack/data/license.json: cannot open file
I don’t know what it means with “license.json: cannot open file”, but in the path /usr/etc/nuitrack/data/ I don’t see the file license.json. I imagine it will be created once I activate the license.

How can I solve it?. My Nuitrack version is 0.34.1.

I was able to active the license (TRIAL and PRO).
The problem was because of the permission of the data folder.
So I run the following command to change the permission :
sudo chown -R $USER:$USER data/

Now I have a license.json and a license.json.lock files in the /data folder.

I can’t execute my program, after 10 seconds the error continues appearing:

…LicenseNotAcquired exception (ExceptionType: 6)

Please help.