I’m using AVAST Internet Security 2014.9.0.2011 , Windows 8.1 X64 and Firefox 26.0
The management page of the router is not opening if the Webshield is turned ON this also happens with other pages located on my Home Server , for example I have a PLEX media server and a HTTP file server all acting the same. If I disable the Webshield all works fine , I’m not sure what is causing this.
I also excluded the 192.168.1.1 - Router and 192.168.1.6 - Home Server from beeing scanned by the webshield and it’s the same:(
As a test, try unchecking “Block Malware URLs” in the Web Shield Main settings…
You might also check the Report File for Web Shield to see if anything was logged. The reports are located in \All Users\Application Data\AVAST Software\Avast\report.
In the Webshield settings try ticking “scan well known browser processes only”
Hi guys and thanks for your suggestion unfortunately none of them seems to fix this issues , the only fix is disabling the Web Shield component 
New avast user and disappointed , probably i rushed to early to buy a license…
In Firefox go to: Tools, Options, Network Advanced, Connections, Settings
and do the following:
1): Add the Address of the Modem or Router … http://192.168.1.1 to the Use No Proxy Box at the Bottom
You will need to check the Use Manual Proxy box first in order to add this.Once you do that then do:
2): Be sure No Proxy is Checked
3): Restart the Firefox browser and then try to access the Router by typing in the numeric http address. You should be fine now.
Let us know how it works out.
That didn’t work for me.
Please read Lukor’s post here regarding an experimental fix for this problem…
http://forum.avast.com/index.php?topic=143211.msg1046637#msg1046637
Gregg
For all of you with this problem, please see what I posted above and give it a try. I know it has to be this way on my computer if I want to see my router interface and I am running XP Pro SP3 with Avast Free (latest release) … For some reason, the web Browser, must know that the Router Interface IP must not use a Proxy or a DNS Server, so you must add it’s HTTP://192.168.1.1 (or what IP yours is at) to the Use No Proxy List … please give this a try and I a fairly certain, in most cases, your issue will be gone.
If anyone is interested in trying it, Lukor has posted about the experimental fix for this router problem. See his post at:
http://forum.avast.com/index.php?topic=143211.msg1046988#msg1046988
Gregg