Hi and welcome to the forum @Anonymous User,
Sorry to hear you're having problems. In order to help you, can you please provide the following information: -
Sufficed to say, the more detailed information you are able to provide, the easier it will be for us and/or the NOW TV developers to work out a solution for you!
Hi again @Anonymous User,
Although the (NetCast) operating system on your LG television is the oldest version that supports the NOW TV app, it should still work. Albeit more slowly...
It sounds like you'll have to perform a 'factory reset' (which can be found via the 'Option' setting). I have to do it every-so often on my LG TV's, that run the older NetCast OS when they become unstable. Which usually occurs after a couple of software updates!
Sufficed to say, a factory reset means you'll have to re-tune all your TV channels and you'll loose all your pre-sets. So make a note of them before you give it a go!