Fireshot Pro, How to revert to Lite after Trial

The Fireshot Pro 0.98.77 browser add-on has a problem on Firefox 41.0+ reverting to Lite if you decide not to license it on every machine you use. Here's how to fix that.

The add-on is a tool for archiving or capturing web content and then editing, saving or sharing it via more conventional means other than as url.

When installing the Fireshot add-on whether downloaded from the authors website, or through the feature Tools : Add-Ons > Add-ons Manager >  Get Add-Ons 

It "currently" installs as the FireShot Pro version in Trial mode.

You can also run into the problem if you already have it installed and "ever" clicked on the   FS Pro!   button after capturing, or use the menu option in the browser Tools : FireShot >  Switch to Pro! 

Once it is in Trial mode at the end of the 30 day trial it will begin tossing Pop Up messages that cannot be easily dismissed. They take you to a purchase page, however the mechanism there for reverting to a Lite edition appears to have some problems.

The add-on is a wonderful product and worth the cost, however it is limited per user and per users personal systems. If you need a copy on a co-workers personal computer, or family member who perhaps isn't going to use it as much. The Lite version is more than enough.

The fix is to close all open browser windows, open a regedit tool and "delete" the key string and value

HKEY_CURRENT_USER\Software\Screenshot Studio for Firefox\fx_prokey

Do not attempt to modify the value from "yes" to "no" it will not be enough. In fact after proving this doesn't work returning to the key will reveal it has been "set back" to "yes".

The entire "fx_prokey" key must be deleted.

Note: This is an evolving bug/problem. It can arise for a number of reasons and conflicts and interacts with various features of  >= 41.0 of Firefox. So this "may work" for you.. or it may not, it may only be contributary. The author is aware of the issue and appears to be trying to debug and help those that run into this bug on the products forums.