Configuration Error 'Membership 'already defined. Where is the problem?

The following error has occurred recently:

Server Error in '/'application.

Configuration Error

Description:An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser error message:Section or group name 'Membership 'is already defined. Updates to this may only occur at the configuration level where it is defined.

Source error:

Line 7: Line 8: <sectiongroup name = "system. web "> Line 9: <section name =" membership "type =" Microsoft. scalablehosting. configuration. membershipconfighandler, memberrole, version = 1.0.0.0, culture = neutral, publickeytoken = b7c773fb1_e7133 "/> Line 10: <section name =" rolemanager "type =" Microsoft. scalablehosting. configuration. rolesconfighandler, memberrole, version = 1.0.0.0, culture = neutral, publickeytoken = b7c773fb1_e7133 "/> Line 11: <section name =" Profile "type =" Microsoft. scalablehosting. configuration. profileconfighandler, memberrole, version = 1.0.0.0, culture = neutral, publickeytoken = b7c773fb1_e7ken "/>

Source file:K: \ mainhostweb \ na57 \ WEB. configLine:9

Show Additional configuration errors:

Section or group name 'Role Manager' is already defined. updates to this may only occur at the configuration level where it is defined. (K: \ mainhostweb \ na57 \ WEB \ Web. config Line 10) Section or group name 'profile 'is already defined. updates to this may only occur at the configuration level where it is defined. (K: \ mainhostweb \ na57 \ WEB \ Web. config line 11) Section or group name 'anonymousidenication ication 'is already defined. updates to this may only occur at the configuration level where it is defined. (K: \ mainhostweb \ na57 \ WEB \ Web. config line 12)

Version Information: Microsoft. NET Framework Version: 2.0.50727.42; ASP. NET version: 2.0.50727.42

I am confused about this error for a long time. The configuration file has been fine before. Why did it happen suddenly? After many surveys, I found that the. NET Framework version was upgraded to 2.0. According to the method introduced on the http://communityserver.org/forums/476116/ShowPost.aspx, changing the version back to 1.1 can solve this problem.