Rails app does not load in Admin.Shopify.Com

[Keemtaker]

I created a Rails shopify app using the Shopify library https://github.com/Shopify/shopify_app . The App works perfect if I access it through foo.myshopify.com/admin/apps/foo but fails to load in the admin.shopify.com with the following error below

From this, it seems like it is a known issue https://github.com/Shopify/shopify-app-bridge/issues/160 . Is there a fix for this and how do I fix it when I used the Shopify app library https://github.com/Shopify/shopify_app ?