How to import certificate chain to ipad

Hi Experts,

We are on BI4.1 SP3, with SSL and sso enabled in the BI platform. We are now planed to implement mobile server. Devices to connect to BI mobile are iPad and iPhones.

I have configured mobile server. When run the link http://servername:port/MobileBIService/MessageHandlerServlet?message=GetVersion

I can get the result: the xml with the correct version no.

But when import the configured connection from iPad, and imported all certificate. we still get below error

As we have certificate chains, as below.

How should be import the certificate to iPad. should we import one by one or shoud import all certificates at once

Thanks,

Youqin