Server Error in '/aa' Application. Could not find the specified membership provider.

i am creating change password page

i already use the website admin tool to create rols and users, then on trying the password change for 1 user it give the following error

Server Error in '/CLINIC' Application. Could not find the specified membership provider.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Web.HttpException: Could not find the specified membership provider.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

enter code here [HttpException (0x80004005): Could not find the specified membership provider.]
 System.Web.UI.WebControls.LoginUtil.GetProvider(String providerName) +1543381
 System.Web.UI.WebControls.ChangePassword.AttemptChangePassword() +102
 System.Web.UI.WebControls.ChangePassword.OnBubbleEvent(Object source, EventArgs e) +114
 System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37
 System.Web.UI.WebControls.Button.OnCommand(CommandEventArgs e) +118
 System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +166



System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13 System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565

my web config

<authentication mode="Forms"/>
  <membership defaultProvider="OracleMembershipProvider" userIsOnlineTimeWindow="20">
<providers>
<clear/>
 <add name="OracleMembershipProvider"  type="Oracle.Web.Security.OracleMembershipProvider, Oracle.Web, Version=2.112.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342" connectionStringName="OraAspNetConString" applicationName="/Clinic" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="true" requiresUniqueEmail="false" passwordFormat="Hashed" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="7" minRequiredNonalphanumericCharacters="1" passwordAttemptWindow="10" passwordStrengthRegularExpression=""/>
</providers>
</membership>
 <roleManager enabled="true" defaultProvider="OracleRoleProvider">
<providers>
<clear/>
<add name="OracleRoleProvider" type="Oracle.Web.Security.OracleRoleProvider, Oracle.Web, Version=2.112.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342" connectionStringName="OraAspNetConString" applicationName="/Clinic"/>
</providers>
</roleManager>