I have deployed a solution with farm scope feature.

I am able to activate / deactivate feature via "Manage Farm feature".

I want to do this via power shell :

When i try to activate feature "Enable-SPFeature -Identity \*14hive\_featurefoldername\* though this command exception is thrown: 

**Enable-SPFeature : Object reference not set to an instance of an object.**

Whereas Disable-SPFeature feature work properly.

What am i missing in Enable-SPFeature statement?