No Extension icon in Firefox

[G Priddy]

I am using Firefox 50.1.0 on Windows 10 updated 12/21/2016. 
VDH 6.1.1 icon does not appear in the toolbar of firefox. 
I can not seem to edit these settings. 
Please help.

[mig]

Can you open about:config, search for parameter browser.uiCustomization.state and reset the value ?
If it's not enough, disable and re-enable VDH. If still not sufficient, try restarting the browser.

[G Priddy]

open about:config, search for parameter browser.uiCustomization.state and reset the value ?
If it's not enough, disable and re-enable VDH. If still not sufficient, try restarting the browser.

Tried that...no help

reinstalled the addon...no help

[mig]

Then sorry but we have no solution other than creating a new Firefox user profile and reinstall VDH to this profile.

[authe...@gmail.com]

This happens to me now and then (Ubuntu Firefox 50.1.0). The way I deal with it is remove the extension and restart Firefox, then reinstall the extension. If you don't restart before reinstalling you may not get the fix.

I did try the about:config solution and it worked after restarting Firefox.

There seems to be an ongoing problem as I have faced this problem several times but I do not yet know the trigger for the disappearing icon. If I work it out I will come back and post. At the moment I suspect it happens after an addon update but I may be wrong and it may be just a coincidence that both events happened around the same time.

Does VDH do any logging?

[mig]

Thanks for the feedback.

VDH does some logging to the console but for this particular issue (the management of the toolbar icon is done by Firefox, not the add-on), you are unlikely to see anything there.

[lanita005]

I had the same problem beginning two days ago.  I have FF 52.0.1, VDH 6.2.0, and Windows 10 Home (Version 1607, Build 14393.953).  I uninstalled/reinstalled VDH, restarted the browser, reset browser.uiCustomization.state, and did so in every combination of sequence one can imagine all to no avail.  In the end, I did a refresh of my FF profile, which (among other things) deleted all my extensions, and then I was able to see the VDH icon in the FF Toolbar after reinstalling VDH.  So if none of the other steps suggested above work for you, try refreshing your FF profile.

Instructions for backing up your old profile can be found here:

http://kb.mozillazine.org/Profile_backup

You can get a list of installed extensions (so you can re-install after refreshing your profile) by copying the page found here (or converting it to pdf) - Help/Troubleshooting Information