Hey Joe D,

You are right that in general 404s in the error log are not of much concern, but I think that there is an actual problem in this case if users click a link on facebook that someone liked and then it results in a 404.

The problem is that he is using non-ascii characters (Greek) in his urls, and though that generally works in the browser, the Facebook like button needs the url to be url encoded.

It is possible that when he changed his site to force Greek culture that fixed it so that url encoding works better. But possibly links that were "liked" before that change still exist on some facebook pages and when people click them it causes this 404 because of the way the urls were encoded.

I have seen this in IE where if you click a link with unencoded non-ascii characters it works, but if you paste it into the url bar IE url encodes it and then it results in a 404.

It can be problematic using non-ascii urls in some cases and I don't have any perfect solutions for it.

I could try adding a setting on our Facebook like button to allow configuring it to not url encoding the url to like, it might work but it might not or might cause other problems.

But I think it would be best to see if it really is fixed by the change to Greek culture and only links created by liking before he made that change are still broken.

Best,

Joe