How to solve this problem

how to solve this problem please need help

Something is generating output before it is expected in file custom-widgets.php: there is an error in that file that is triggered early, maybe it is outputing something it should not be (empty line after ending PHP ?>) or something similar.

I think you printed something before wordpress sessions,so try to remove it .
You can contact me if you need more help at or skype me at pradeep.narava