The Membership ID cannot be found when. net4.0 is used to develop MySql-supported Membership.

When using the System. Web. Security. MembershipProvider class in. net4.0, it must be referenced: System. Web. dllSystem. Web. ApplicationServices, Version4.0.0.0, Cultureneutral, failed. Otherwise, the MembershipProvider class cannot be found. Solved this problem

In. use System. web. security. the MembershipProvider class must reference: 'System. web. dll ''system. web. applicationServices, Version = 4.0.0.0, Culture = neutral, PublicKeyToken = 31bf3856ad364e35 '. otherwise, the system prompts that the MembershipProvider class cannot be found. Solved this problem

When using the System. Web. Security. MembershipProvider class in. net4.0, you must reference:

'System. Web. dll'

'System. Web. ApplicationServices, Version = 4.0.0.0, Culture = neutral, PublicKeyToken = 31bf3856ad364e35 '.

Otherwise, the system prompts that the MembershipProvider class cannot be found.

After solving this problem, we can try Membership to connect to the MySql database.