App Store has disappeared from MacBook Air
I have searched high and low over the past few months and cannot find any examples of an issue like this one... I have not been able to open my App Store for a long time now. When I click on the icon, it 'bounces' on the dock for half a second before disappearing. It won't open. I've tried to go in and clear the caches (e.g. com.apple.appstore and similar) but there aren't any. It's as though all trace of the store has disappeared from my computer, other than the icon. I've tried resetting Safari, clearing the caches on there, safe booting the laptop, and every other fix I can think of. I've tried downloading a combi update from Apple but it won't load once it's downloaded.
I can't update my OS (currently running Yosemite 10.10.5) despite trying through every avenue I can think of. As a result I am now finding various features on the MacBook will no longer work.
Please, if anyone has any suggestions or a solution, I'm honestly at my wit's end.
MacBook Air 11″, OS X 10.10