Wiped out tabs, can't return to websites, website addresses are deleted.

I installed this with tabs open in the firefox browser. When I changed to the tabs, the contents would be replaced with an ad for Blocksite. When I hit the back button the contents would be replaced again.

When i disabled Blocksite from Manage Extensions, those all tabs were closed. Looking in history/recently closed tabs, i don't see my tab names, it only says 'blocksite', when I reopen those, the tabs are opened with a blank pages, (with an web address of moz-extension://1a433477-5e82-4f78-b348-a664e3101618/blocked.html) and the back button is grayed out.

Essentially, BlockSite causes me to loose the tabs I had open and deletes the webpage address.

For some reason I cant find the options to control blocksite, add/remove websites, or even see an icon at the top of firefox. The only thing i see is the Enable and Remove buttons in Add-ons (Ctrl+Shift+A). There is no Options button, (like I have for Adblock Pus), so I can't control the add-on or even block spyware data collection.

This is after installing blocksite from https://addons.mozilla.org, adding a problem website address, and then closing the web page that allowed me to add the address to block.

Firefox Quantum 67.0.3 (64-bit) on a Win7 PC.