Authentication problem with openFire 3.10.2

Hi:

I am using XMPPFramework for iphone and OpenFire 3.10.2. I am able to register using an iphone using OpenFire 3.7.1 however when I have updated to 3.10.2 I get this error.

I have seen that it is a problem with the certificate so I put the client server certificate as optional but I am not able to make it work. The really strange thing is it is working with the old version.

What do you think? Could you let me know if I need to make any change?

Kind regards and thank you for your help.