If any of you happen to have the above message “FireShot Pro trial expired.”, this is what you want to do:
Start regedit.exe with admin privileges and search for “fx_prokey” (depending on how you installed your software – from firefox/chrome, using installer – it has a different location). You will find something like this:
Just change the yes to no, and your problems will be over. This fix should work on any kind of browser.