Welcome the Technical Support section. Help us in assisting you by providing us with a concise and descriptive elaboration of your issues. Be specific and if possible, provide us with a step-by-step instruction in replicating your problem.
this issue not a bug. but conflict with 3rd party extension or there is any customization that you made. please edit your first post at this topic and put valid backend access detail. I need it for debugging purpose.
the issue from 3rd party template. that template only for jomsocial 3.1.x
here what I did to tackle this issue.
jomsocial backend > configuration > templates. and select default as template.