Установить requireQuestionAndAnswer = "false" в вашем web.config
т.е:.
<membership defaultProvider="MySqlMembershipProvider">
<providers>
<clear/>
<add name="MySqlMembershipProvider"
type="System.Web.Security.SqlMembershipProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
connectionStringName="LocalSQL"
enablePasswordRetrieval="false"
enablePasswordReset="true"
requiresQuestionAndAnswer="false"
requiresUniqueEmail="false"
passwordFormat="Hashed"
maxInvalidPasswordAttempts="15"
minRequiredPasswordLength="5"
minRequiredNonalphanumericCharacters="0"
passwordAttemptWindow="10"
passwordStrengthRegularExpression=""
applicationName="/"/>
</providers>
</membership>