I have had no luck getting the tennant context to work.
[tennant_1]
master_key=nosecrets
user:1000:1234:all
buttonfile=tennant01_buttons.cfg
It just won't login to the http://192.168.0.10/fop2/?context=tennant_1
This is what your context should look like:
[tennant_1]
master_key=nosecrets
user=1000all
buttonfile=tennant01_buttons.cfg
Where you have a colon after user it should be a equal sign. Then browse to http://192.168.0.10/fop2/?context=tennant_1 and you'll be set.