Access Denied: "microsoft.web.ui.webcontrols" workaround

ERROR:
Configuration Error
Description: An error occurred while processing the configuration file required to service this request.Please check the specific error details below and modify the configuration file appropriately.

Parser Error Message: Access Denied: "microsoft.web.ui.webcontrols".

Solution:
The most common cause is the Indexing service.The solution is to disable the Indexing service, or configure ASP.net's temporary directory not to be affected by the Indexing service.

The steps to configure the temporary directory of ASP.net not to be affected by the Indexing service are as follows:

1. Start--Administrative Tools--Computer Management (Location of Win2003, similar to other operating systems) Open Computer Management
2. Expand the "Services and Applications" node in the left tree of Computer Management, then expand the "Indexing Service" node under it, then expand the "System" node under it, and then expand under it "Directory" node.
3. On the right side of computer management, we can see the configured indexing service directory.
4. Right-click on the "Directory" node and select "New"--"Directory"
5. In the "Add Directory" dialog box, enter the temporary file of ASP.net through the input boxTable of contents.The default should be:
c://Microsoft.NET/Framework//Temporary ASP.NET Files directory.
refers to the .net version you are dealing with.
6. In the "Include in Index?" option, select "No"
7. Click the "OK" button
8. Right-click on the "Indexing Service" node and restartindexing service.