Hi Paulino,
There is a bug in C/NET 6.9.3 and 6.9.4 on web providers registration.
To fix it you just need to remove ".v20" from type in web providers section in machine.config file (usually located in C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\machine.config) as follow:
<system.web>
<processModel autoConfig="true" />
<httpHandlers />
<membership>
<providers>
<add name="MySQLMembershipProvider" type="MySql.Web.Security.MySQLMembershipProvider, MySql.Web, Version=6.9.3.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" connectionStringName="LocalMySqlServer" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="true" applicationName="/" requiresUniqueEmail="false" passwordFormat="Clear" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="7" minRequiredNonalphanumericCharacters="1" passwordAttemptWindow="10" passwordStrengthRegularExpression="" />
</providers>
</membership>
<profile>
<providers>
<add name="MySQLProfileProvider" type="MySql.Web.Profile.MySQLProfileProvider, MySql.Web, Version=6.9.3.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" connectionStringName="LocalMySqlServer" applicationName="/" />
</providers>
</profile>
<roleManager>
<providers>
<add name="MySQLRoleProvider" type="MySql.Web.Security.MySQLRoleProvider, MySql.Web, Version=6.9.3.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" connectionStringName="LocalMySqlServer" applicationName="/" />
</providers>
</roleManager>
<siteMap>
<providers>
<add name="MySqlSiteMapProvider" type="MySql.Web.SiteMap.MySqlSiteMapProvider, MySql.Web, Version=6.9.3.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" connectionStringName="LocalMySqlServer" applicationName="/" />
</providers>
</siteMap>
<webParts>
<personalization>
<providers>
<add name="MySQLPersonalizationProvider" type="MySql.Web.Personalization.MySqlPersonalizationProvider, MySql.Web, Version=6.9.3.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" connectionStringName="LocalMySqlServer" applicationName="/" />
</providers>
</personalization>
</webParts>
</system.web>
You can also track the bug status here:
http://bugs.mysql.com/bug.php?id=74080&thanks=1¬ify=71
Regards,
Roberto