Add media not working

I am using wordpress on my site tourmet.com.

Now i get problem in “add media” button. this button is work only once in a day. when all my colleagues start there computer in mornning the add media button work for only once. then it is dead for all day. even if we use diffrent browser the problem persist.

We try to change the old JV folder file and all other things but there is no help.

You can imaging how hard to word on wordpress without this add media button. (we try deactivating all the plugins and themes too.)

Please help to solve the problem.