Therefore to solve this problem the simple solution for that is to modify your robots.txt file in your root directory

and add the following at the end

Disallow: /ScriptResource.axd
Disallow:/WebResource.axd

With this no more issues regarding invalid padding.

If this does not solve your issue you can take a look at what other users propose here.

Some update on this issue, i found out while googling some days back:

On this post you can find out how to compress the webresource.axd and also somewhere in between prevent this error to occur.
http://mironabramson.com/blog/post/2007/10/New–Shiny–WebResourceaxd-compression-Module.aspx

Use the tool found at the website below to generate a machine key and a decryption key:
http://www.orcsweb.com/articles/aspnetmachinekey.aspx

Case study:

e.g http://www.somesamplebigsite.com/product.aspx?q=123&u=09#description
The url above send the user to a page product and then your browser interpret the anchor and scroll down way to the description anchor. But the question is why the heck would i want to get the anchor since it’s just an anchor ? There might be several reasons for that. Here is 2 of them:

• You might not want to pass an extra parameter in your URL query string because of Referencing issues
• You would like to perform an action when the page reaches the anchor: Example open an AJAX popup or load some information or Execute a JavaScript in the Description Section of the product.

There might be several other reasons, but these two give you and idea of what is to be achieved.

You can’t get access to the anchor value using server side ASP.NET, it will neither be seen in the Request.Url nor the Request.RawUrl. Therefore those who are trying in vain to get access to this information, don’t bother anymore. You can just use a simple javascript that will do that, and then if you want afterward to either make a new submit to the server or do it in AJAX.

var anchorValue;
var url = document.location;
var strippedUrl = url.toString().split("#");
if(strippedUrl.length > 1)
anchorvalue = strippedUrl[1];

With these few lines of javascript you will be able to determine the value anchor that has been sent in your URL.