Contact it's support site.

Could you check the version 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 on the right side find PasswordBox. If it is disabled, it will be out of alphabetical order at the bottom of the list.

Click the More link to confirm that you have version 2.0.0, which has files dated 8/18/2015 inside. Up to date?

If the extension is already enabled and/or clicking the Enable button does not restore the toolbar button:

Occasionally if you end up with too many buttons/icons on the toolbar, some controls will "overflow" onto a drop-down. The button for the drop-down has a >> icon. If you find that, you can use Customize to move the PasswordBox button into a more useful location.

If it's not there either, consider using the "Restore Defaults" button at the bottom center of the Customize tab to return the toolbars to "factory" defaults. This article has the details on Customize: Customize Firefox controls, buttons and toolbars.

Then disable/enable PasswordBox to trigger it adding its button back to the toolbar. Success?

If the Enable button is missing:

You might have accidentally turned on the signature requirement. You can turn that off here:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste xpi and pause while the list is filtered

(3) If the xpinstall.signatures.required preference is bolded and user set to true, double-click it to switch it to false

If the preference indicates it is locked, we need to investigate an autoconfig file. If it changes back to true at the next startup, we need to investigate a possible user.js file.

Thank you for your reply...... This is what I found:

• The icon (and information) for PasswordBox is listed and it is version 2.0, and the only two buttons available are "Disable" and "Remove." There is no "Enable."

• It didn't appear that the PWB icon was in a drop down, and I went ahead and clicked "Restore Defaults." Nothing happened that I can see.

• Then I did the about:config thing, and the link was not bolden and was set to "false."

So, I am back to square one. PWB is downloaded, the icon shows in the Ad-On's section, but yet it is not on the tool bar like it used to be, nor is it operational.

Any other suggestions?

Thanks again........

The button is either labeled as 'Enable' when the extension is currently disabled or is labeled as 'Disable' if the extension is enabled (i.e. shows the opposite state). You will never see both of them as that wouldn't make sense. So if you see 'Disable' then the extension is currently enabled.

As a test I installed Password Box and the icon was added to the toolbar. I removed it after that, so I don't know whether it would have been lost later. However, if it never even showed up for you after reinstalling, I wonder whether there might be a conflict with another extension. Could you try disabling all the extensions you can live without for 24 hours to see whether that helps?

The "enable" theory, that is correct. Thus my comment about the disable button is evident and the enable button was not - meaning that it is enabled; downloaded; and active - but not showing on the tool bar nor working. The thing is, PWB was working just fine about a week ago.

I will try the 24 hour test and see what happens. However, the only two add-ons I see listed is PWB and AdBlock Plus - which I have disabled for the test. Should I search anywhere else?

Thanks everyone for your help. It is greatly appreciated. But, I am still at square one.

Hope to hear from someone again soon.

Did you try to close and restart Firefox or possibly open a new window when the button disappears or in malfunctioning?