sorry,it isn't avast's problem.

Avast Free Antivirus / Premium Security
1

If I stop avast! shields for a while ,then restart it , the SCAN FOR WINDOWS EXPLORER in Right menu is disappeared !!

only Reinstall avast can solve the problem! :cry:

I use a Trojan scanning software ,it Wrongly clean the avast’s ashshell.dll .So sorry ,it’s not a bug!

2

Please be more specific.
The Shields have nothing to do with the right-click scanning option.
If reinstalling Avast has solved it then it’s Ok.
It cannot possibly be a 5.0.454 bug though I am not sure about it.