Possibly if you do not edit your question for language as this is a public forum.

XPinstall.signitures.required was for Extensions not Plugins, and it went away with Firefox 48 and later; so that isn't even related to your issue.

Firefox 52 deprecated all NPAPI Plugins except for Adobe Flash Player; so that is probably why Foscam cameras aren't working.

The Firefox ESR 52 version does continue to provide support for most NPAPI Plugins; that is the current Extended Support Release version that will be around until at least Aug 2018 with security updates. Firefox ESR 52.9 on 07-03-2018 is slated to be the final version of ESR 52.

Get ESR 52 here: https://www.mozilla.org/en-US/firefox/organizations/

Pkshadow said

Possibly if you do not edit your question for language as this is a public forum.

Pkshadow, please try to focus on the question the user is asking, not how they are asking. As much as I would also like every user asking for support to have the perfect language, this is just not something to expect from me or even you.

As for the thread here, please consider the-edmeister's suggestion for support and post back here. I will be monitoring this thread.

Well didn't think the language was that offensive sorry. I have been dealing with this problem for a long time and quite tired of it and have tried several suggestions that have lead nowhere, so you must see my frustration? What can be done about getting this figured out?....If I agree to changing these settings to false, then the ramifications is on me, I am willing to take that chance so I can use my cameras. I have a business to protect and can't use my cameras because you have blocked my abilities to do so? What can I do, or what needs to be done to get my extensions to work correctly? Am a bit confused as they say plugins not installed, click on that and down load the "plugin", then says signitures required? Please tell me what can be don't to bypass this. Thanks Pat

Can you confirm that this is about installing a plugin (which plugin or extension)?

• "3-bar" menu button or Tools -> Add-ons -> Plugins

Note that Firefox 52.0.2 you appear to use is likely a release version and not the Firefox 52 ESR version. The Firefox ESR version should support xpinstall.signatures.required, but the Firefox 52 release doesn't and can't install unsigned extensions.

• Help -> About Firefox

Firefox 52.5.3 ESR:

• https://www.mozilla.org/en-US/firefox/organizations/all/
• https://www.mozilla.org/en-US/firefox/52.5.3/releasenotes/
• https://www.mozilla.org/en-US/firefox/52.5.3/system-requirements/