A public action method pagerror.gif / refresh.gif could not be found on controller - who is calling that gif?

Hello stackoverflow world. (This is the first time I actually post a question here. Exciting)

A while ago I inherited a 2 year old MVC website from one of the teams within my corporation. I know most the ins and outs of this solution now but there is something strange cropping up in my error logs which I do not understand.

Every now and then I will get an error messages like this one:

A public action method 'xyz.gif' could not be found on controller MyNamespace.MyController

What I don't understand is WHY is this action (a gif image) being called in the first place?

I've seen 2 different gifs in开发者_C百科 the error logs pageerror.gif and refresh.gif

As this is an inherited solution I double checked everything and made sure that there are in fact no images like that in the project and no reference anywhere even to those words in the controllers, views, style-sheets or even in the source of pages within the same controller.

I seriously doubt that the users are playing around with the URLs and adding random gif names to them to see what happens.

I'm all out of ideas. Anyone out there who can suggest more places to look for the culprit?

Ta!

As Tchami pointed out in a comment on the original question, this is related to Internet Explorer's default error pages.

As I have set up custom error pages I believe this is either due to an internal server error or possibly somehow an action cancel error from the client side, i.e. client side error. I can't be 100% at this point.

The question is not fully answered but I mostly know what the cause is now.

From my point of view I've identified that I need to improve this ASP.NET MVC application so that

1) it doesn't report/log errors when someone tries to navigate to a non-existing controller action (e.g. these refresh.gif actions or any other)

and 2) handle it better for the client so that they don't end up clicking from one error page (default IE error page) to another (my custom error page when clicking the refresh icon on the IE page)

Another stackoverflow thread on a related topic:

Significance of 'pagerror.gif'?

(i can't post more links as I'm a new user)

CHEERS!

Solveig

Can you get the error to show up in the logs when you use the site yourself? If so, an add-in such as HttpWatch might help you see those .gif requests. If you can understand more about when they happen you might be able to figure out what's going on.

Pagerror.gif and refresh.gif are the default images from the IE browser/IIS server. Normally these images were shown when the browser is not able to retrieve the content.

If you see these errors in logs, then check the iis log to get more information.

For example,

IIS Log : look for this feild ,

cs(User-Agent)

compatible;+MSIE+6.0;+Windows

Here few things to be noted,

1)IE 6.0 apparently makes these requests on its own. I am not sure if any other IE 6+ Browser would show similar behavior.

2)All this will do is generates a 'bogus" event log entry because a null reference exception could happens when you request a non-existing GIF and that request goes through MVC pipeline.

3)Technically this simply can be ignored.

4) Optionally we could check if through routing we could stop “.gif” files from being processed by MVC Pipeline

All i would suggest is to handle it gracefully.

It may be difficult to pinpoint this, but my thought would be: check the javascript. If the image name is being dynamically generated somewhere, and then requested, a simple "find and replace" may miss the reference.