MerchantPlay offline capabilities rely mainly on the HTML5 cache.manifest. Sometimes you would need to flush the cache.manifest to solve some of the persistent problems that are otherwise cannot be resolved using all other means.
Getting rid of a cache.manifest file in chrome is a bit tricky. It can't be flushed by just clearing the cache.
To view all Application Caches you can type:
chrome://appcache-internals/ in the address bar.
You should see a list of all apps that use a cache.manifest file and can now view their entries to remove the Manifest from Chrome.