Most IE Add-ons disabled/unavailable and enable buttons greyed out

Avast Free Antivirus / Premium Security
1

Running Win 7 Professional N, 64 bit, SP1, with all important updates installed and current Avast Pro.

IE11 (and now back at IE10) started telling me it needed flash (which was already installed). Repeated installs from Adobe site and still unable to show flash videos. Then noticed “Send to OneNote” option disappeared from command menu. Add-on manager showed “Send to OneNote” unavailable and nearly every other add-on disabled including all the Microsoft “Run without permission” ones like Silverlight, XML, etc. All had their Enable/Disable buttons greyed out. I uninstalled IE11 and reinstalled, I uninstalled back to IE10, I repaired Office 2010 Pro, used malwarebytes, Spybot, CCleaner and MS Safety Scanner. So far, nothing gained. “Enable third party browser extensions” is checked under Internet Options.

Strangely, I have the same problem on my laptop running IE 11, Windows 7 Professional, SP1, 32 bit.
Could a setting in Avast be causing this?

John

2

Update:
I rebooted in safe mode with networking (i.e. Avast off) and found that the add-ons were all enabled. So does that make it an Avast problem or something else?

John