I can't install any plugins
I bought license, logged into fop2 admin panel.
And i see 'There are no licensed plugins'
I also tried this:

# /usr/local/fop2/fop2_server --test
unable to initialize libusb: -99
Flash Operator Panel 2 - Valid License (/usr/local/fop2/fop2.lic)
Flash Operator Panel 2 - Featureset: Basic
Flash Operator Panel 2 - Allowed Tenants: 5

Connection to manager OK!

# /usr/local/fop2/fop2_server --plugins
unable to initialize libusb: -99

It doesn't work on SNG7 (Distro with FreePBX14 and Centos 7)
FreePBX 13 Distro (with Centos 6.6) works fine