Another user who can't use it after the Firefox upgrade to 60.0 and keep getting the "cannot be installed because it is not compatible with Firefox 60.0" message.

I did the following and I still cannot get Fireshot installed

1. Removed Fireshot from Firefox addons as you suggested
2. Closed and reopened Firefox, tried to install Fireshot and still get the incompatible message
3. Rebooted computer, opened Firefox and tried to install Fireshot and once again still get the incompatible message.

How do you do a manual extension update check as you suggested to another user.

Please get this sorted as I've tried a few other screenshot addons and they are hopeless compared with Fireshot when it works well.

UPDATE: I installed Fireshot 0.98.94.11 following anonymous user 7756d5's suggestion and Fireshot is once again working in Firefox for me. Many thanks for the suggestion :) And I've updated my rating as well :)