NS thinks new tab in FF is always about:newtab

[editer]

Hi folks. I didn't see anything in search about this so I'm asking here. I'm using NS 5.1.4 in Firefox56.0.1, and a lot of the time when I open a new tab, and occasionally a new site in an existing tab, I try to allow scripts on the page and NS only gives the option of "Allow about:newtab" or "Forbid about:newtab" depending on the last action on about:newtab.

This happens even when Firefox's address bar shows the actual page I'm trying to read, and the window shows whatever content is allowed with scripts blocked.

I haven't a workaround that works consistently. Sometimes copying the URL into an older tab works and sometimes not, it seems.

Has anyone seen anything like this before?

Thanks!

[Giorgio Maone]

I didn't see it (obviously) but I can see it now
Investigating, thanks.

[Giorgio Maone]

BTW, I cannot reproduce on a clean profile (56, 57 and 58).
Could you provide me with the list of your extensions from about:support, and possibly try Standard Diagnostic|sd? Thanks!

[editer]

Thanks, Giorgio. Here are my extensions.

Enabled:
Adblock Plus 2.9.1
Add to Delicious+ 1.06.1-signed.1-signed
Evernote Web Clipper 6.13
F.B Purity - Cleans up Facebook (WX) 19.1.0
Greasemonkey 3.17
LeechBlock 1.0.8
NoScript 5.1.4
Privacy Badger 2017.9.12.1
Recall Monkey 22.1-signed.1-signed
Reddit Enhancement Suite 5.8.6
Safe Browsing Version 4 (temporary add-on) 1.0.0
Saved Password Editor 2.10.3
Screengrab 0.96.3.1-signed.1-signed
Stylish 2.0.7
Theme Font & Size Changer 56
U2F Support Add-on 1.0.1
Video DownloadHelper 6.3.3
Wallflower 1.5.1.1-signed.1-signed

Disabled:
feedly 16.0.528.1-signed.1-signed
Ghostery 7.4.0.5
McAfee WebAdvisor 6.0.0.117
Silvermel and Charamel XT 2.0.2
Webroot Filtering Extension 1.4.0.8

I'll go try the standard diagnostic now.

[editer]

I restarted FF in safe mode then back in standard mode, and now I can't reproduce the problem (Edit: I was trying to do the disable-half-of-the-extensions thing). I'll keep an eye out and keep you posted.

[editer]

OK, I didn't notice this for a while, but then just now I noticed I went to gamespot.com and NS thought it was on wikipedia.org. I tried pasting the URL into a new tab and NS thought it was on about:newtab. I disabled a few add-ons (AdBlock Plus, U2F Support Add-On, Video Downhelper) and restarted FF, and now it's working fine.

Further bulletins as events warrant. Thanks!