What is the aspnet_client Folder?
Written by Naveed Ashraf Monday, 31 January 2011
Applied to: Windows Hosting Plan
ASP.net developers should be aware of the aspnet_client folder in their web space. This folder is related to ASP.net runtime validation and has its own importance. This folder is automatically created when you enable the ASP.net extension on your site. The aspnet_client folder contains the client-side code used by some of the ASP.NET Web Form controls (namely validation, SmartNavigation). The scripts contained in this folder get called by web pages that utilize controls that need these scripts. If you use a control that uses one of the scripts in this folder and the script can’t be found, then that control will not be able to do its client-side job.
The aspnet_client folder should be considered as the ASP.NET runtime component not your ASP.NET application. The scripts in the folder might change in the new version. This is why Publish Site tool will delete it first and then ASP.net will recreate it. If you had a web application developed in an older version, then published it to a web site with a newer version of ASP.NET, the aspnet_client should have the scripts from the same version of ASP.NET. So it is a good practice to let ASP.NET maitain this folder.
If your aspnet_client directory is missing, you may encounter errors with your application such as “Unable to find script library ‘/aspnet_client/system.web/1_0_3705_272/webUIValidation.js’. To resolve this, you can manually copy the folder to the root directory of your domain name.