Netflix won't work on Lenovo Ideapad A3000?

There must be a glitch. I'm guessing you have windows 8? If yes, then swipe from the left (or point mouse in the upper left corner) and loook for the netflix app. Right click it(or hold it) and click "close". That should fix your problem.
if it doesn't then open task manager. The easiest way to do it is to open up "charms" (swipe from the right or point mouse in the upper right corner) click the search button and type in task manger. Open the first one. Look for the netflix app, select it and press "End Task". Then press the "More" arrow and look for netflix. There may 1 or 2 version of it, 32 bit and 64 bit. End both tasks. That should solve your problem. If not, check if there's an update in the Windows Store for netflix. Most updates fix those kind of bugs. If there isn't an update, then simply reinstall the application.

Has it ever worked, if so then try removing the app from windows 8 if its the app, if not then you may need a plugin.