Am confronting yet another uMatrix popover that only displays a big orange caution sign, the URL uMatix has blocked and a CLOSE button. The rest of the page is white space.

A GitHub page looked promising -
How to get past "uMatrix has prevented the following page from loading" - -
https://github.com/gorhill/uMatrix/wiki/How-to-get-past-%22uMatrix-has-prevented-the-following-page-from-loading%22

Trouble is, unlike the VERY nifty new-for-1.1.14 feature Ray described in great detail at the bottom and that I've already used a number of times (it parses URL parameters and really does give the intended hyperlink so you skip over the ad garbage and go directly to the page wanted) the top screenshot and explanation is incorrect, at least for me.

For example, when I visit an AT&T site to rant, a Feedback tab appears on the right side. When clicked, uMatrix generates a popOVER window up stating - uMatrix has prevented the following page from loading: https://secure.opinionlab.com/ccc01/comment_card_d.asp

Unlike his screenshot, these popover pages lack the isolated uMatrix icon or a tab on the top bar of the window (though there's one inside the address input line that doesn't do much) that standard FF browser windows would have. It lacks all of the typical FF icons - back arrow, refresh, search. There's just a very wide address window and the 3-barred settings icon at the far right.

That big Caution sign might as well be a Dead End sign. I'm still unable to find a way to UNPREVENT (disable) the uMatrix block! Help??

Also, I must not understand this review page's GUI. The review/question I posed a month ago that the dev kindly answered with info that others might benefit from reading has disappeared, with no warning that I was overwriting it by posting this second question a month later. It was still visible just before I posted this one. Any ideas wot hoppened??