SharePoint 2013 LDAP FBA people picker configuration in Mixed mode

Hi,

I have configured SharePoint 2013 extranet web application (hhtps) in mixed mode with LDAP FBA and ADFS trusted authentication (this is for implementing a multi-tenancy solution) .

I am facing the below issue while searching for LDAP FBA users in the people picker.

"Sorry, we're having trouble reaching the server.".

Also, the entire login process works fine. 

I also have the below entries in web.config of SP central admin and the web app itself.

<PeoplePickerWildcards>
      <clear />
      <add key="AspNetSqlMembershipProvider" value="%" />
      <add key="DemoLdapMember" value="*" />
      <add key="DemoLdapRole" value="*" />
    </PeoplePickerWildcards>

However, the people picker works fine in SharePoint central administration web application.

Profiling the network shows "500 internal server error" for the below resource.

https://{{webappname}}/_api/contextinfo

I can see the same error in the ULS logs.

Please let me know am I missing anything here.

Thanks,

Srikanth