In order for Firefox to allow Insightful to collect usage data, Accessibility service should be enabled in the browser settings.
Enabling Firefox Accessibility Service
Type about:config in the address bar and press Enter,
If a warning page appears click Accept the Risk and Continue to move forward to the about:config page,
In the about:config page, search for the preference accessibility.force_disabled,
Observe the Value column of the accessibility.force_disabled row.
If it is set to 0 then you dont have to do anything.
If it is set to 1:
double-click on it to open an editing field,
type 0,
click the blue check mark button or press the Enter key to complete the update.