Some sites produce the "Oh No!" error when extension is active.

[Google Code Exporter]

1. activate the extension and make sure that it is filtering
2. open google.com
3. wait it till it is finished loading.

the very moment it is done loading it turns into a "Oh No!" error page even 
though it was loading and showing fine until then. Also it doesn't occur when 
filtering is disabled (not the extension, just the filtering)

Also: "Oh No!" error pages becoming a regular while filtering is active (well I 
couldn't figure out the pattern ... but on google.com it happens every time) 
while I almost never see them when filtering is off.

Original issue reported on code.google.com by [e-mail] on 20 Mar 2015 at 11:55