IIS7.5 detailed error HTTP Error 500.19

When I log on to the ArcgisServer Manager, the following error is reported:

Module IIS Web Core
Unknown notification
The handler has not been determined
Error Code 0x800700b7
The configuration error defines the repeated "system. web. extensions/scripting/scriptResourceHandler" section.
Configuration file \\? \ C: \ inetpub \ wwwroot \ ArcGIS \ Manager \ web. config

16: <sectionGroup name = "scripting" type = "System. Web. Configuration. ScriptingSectionGroup, System. Web. Extensions, Version = 3.5.0.0, Culture = neutral, PublicKeyToken = 31BF3856AD364E35">

18: <sectionGroup name = "webServices" type = "System. Web. Configuration. ScriptingWebServicesSectionGroup, System. Web. Extensions, Version = 3.5.0.0, Culture = neutral, PublicKeyToken = 31BF3856AD364E35">

Solution:

According to the configuration error prompt, the "system. web. extensions/scripting/scriptResourceHandler ", I open the configuration file web. config, remove the red part, and then log on again. If there is still an error, delete the repeated definitions that appear again.

Finally, you can log on .... However, at present, I do not know whether deleting these bytes will affect the future ...?