Rated 5 out of 5 stars

Icon missing from the toolbar. Right click does not open links anymore.

I am using the lastest version, 0.3.8.4.1. I hope the problem can be resolved. This addon is an absolute necessity for me.

This review is for a previous version of the add-on (0.3.8.4.1-signed.1-signed). 

Oh, sorry for late reply, I somehow missed your review...

Please check "Enabled" checkbox in options.
And "Options - Enable right-click"/"Options - Enable long left-click".
Or the same in about:config:
extensions.rightlinks.enabled = true
extensions.rightlinks.enabled.right = true
extensions.rightlinks.enabled.left = true

Toolbar button is probably inside "Customize…" from toolbar context menu. Or this is conflict with another extension...