Hi RobinClaire, when I replied to your post in the other thread I didn't realize you had your own question. I'll repeat that here:

The "red button" to install is on this page:

https://about.pinterest.com/browser-button

The actual file loads from this address:

https://assets.pinterest.com/ext/Pinterest_Firefox.xpi

When sites push an add-on from a different host name (the bold part is the host name), Firefox should install it anyway after you click Allow for the site. However, some users get the connection error in this scenario. I suspect it's related to their security software, but I haven't seen a definitive explanation yet.

One workaround assuming you trust my link is this procedure:

(1) Right-click the direct link to the .xpi file, and Save Link As to your computer.

(2) Install it using the menu on the Add-ons page. Either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Extensions. Then, above the list, look for the button with the gear/cog/wheel icon, click that and choose Install Add-on from File... That should display a dialog you can use to find and install the Pinterest extension (.xpi file you saved).

One negative of installing this way is that Firefox can't check for updates the way it can when you install directly from a website.

I didn't save an xpi pinterest file yet. how do I do that?

before it said 'connection failure' it said... "Firefox prevented this site from asking you to install software on your computer" (allow/not now are the options).

I clicked on "allow".

Yes, the normal sequence for installing from a not-yet-trusted site is that you first get an allow button, then a panel with Install and Cancel.

To do a local install-from-file, right-click the following link and use Save Link As:

https://assets.pinterest.com/ext/Pinterest_Firefox.xpi

Then use the steps I mentioned in the earlier reply.

Thank you very much. I got it. Robin