HELP

Unable to load mono library from “C:/Program Files (x86)/Unity/Editor/Data/Mono/EmbedRuntime/mono.dll” (error = 126).

please explain why this is happening

Sounds like problem with unity and not a scpecific project, try reinstall.

See:
http://forum.unity3d.com/threads/195932-Error-126-(Unable-to-load-mono-library-from-)

And next time, give a proper thread title in the correct section.