i just update jomsocial to jomsocial 4.2.1 and since then i am seing blank page. how to do? help

Hi
As I can see there is no plan active on your profile, so I am not sure how and from where you found the Jomsocial package.
If you have another account on Jomsocial, I suggest you to repost the question on the forum and also submit the site details for Mods/Staff when you add the new thread.

As per support policy support is limited to active members only.

Regards