newtonsoft.json error[Urgent]

Hi all,

I have Visula Studio 3.5 in my system .i have taken project from my server,but when i am running it is shwing below error.

could not load or assembly 'newtonsoft.json or one of its dependencies.this assembly is buily by a runtime newer than currently loaded and can not be loaded.

even dll is alredy there for it(Newtonsoft.Json.dll),what should i do?

Please help me for this

Thanks in advance

Honey