We keep getting "Connection string cannot be blank" for custom membership provider implemented in SharePoint using custom database and below is configuration part in application , central admin and SecurityToken, any idea please:
<system.web>
<membership defaultProvider="i">
<providers>
<add name="i" type="Microsoft.SharePoint.Administration.Claims.SPClaimsAuthMembershipProvider, Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />
<add connectionStringName="OTHConnectionStringName" name="OTHMembershipProvider" type="OTH.FBA.Providers.OTHMembershipProvider, OTH.Intranet.FBA, Version=1.0.0.0, Culture=neutral, PublicKeyToken=0194fee1bb29930b"
enablePasswordReset="true" enablePasswordRetrieval="false" passwordFormat="Clear" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" applicationName="/" passwordStrengthRegularExpression=""
minRequiredPasswordLength="3" minRequiredNonalphanumericCharacters="0" maxInvalidPasswordAttempts="9999" />
</providers>
</membership>
<roleManager defaultProvider="c" enabled="true" cacheRolesInCookie="false">
<providers>
<add name="c" type="Microsoft.SharePoint.Administration.Claims.SPClaimsAuthRoleProvider, Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />
<add connectionStringName="OTHConnectionStringName" name="OTHRoleProvider" type="OTH.Intranet.FBA, OTHRoleProvider, Version=1.0.0.0, Culture=neutral, PublicKeyToken=0194fee1bb29930b"
applicationName="/" />
</providers>
</roleManager>
</system.web>
<connectionStrings>
<add name="OTHConnectionStringName" connectionString="Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=FBA_DB;Data Source=." providerName="System.Data.SqlClient" />
</connectionStrings>