Shopify App is not loading in new unified admin although working fine with old domain*.myshopify.com

[neomi-dov]

Hi, I have developed a Shopify App using PHP(Laravel Framework). This app is working fine with *.myshopify.com but app is not loading on new Shopify unified admin admin.shopify.com. 
I have already followed the instructions and verify that CSP and host parameter base64 is fine but still it's not loading on unified admin and automatically open app in old domain(*.myshopify.com) in new tab and showing me message

"APP_NAME will open in a new tab

This app is taking a while to load. If you are not automatically redirected, click to open the app now."

My loads faster and I don't see any issue in loading time. Can someone help me here to point out what mistake I am doing and what other things I need to take care of to make the App work with unified admin. Thanks In Advance.

[locomojo]

I'm having the same issue with my PHP Shopify App. It would be great if Shopify would provide some better guidance on how to update our apps. I'm wondering if the oAuth URL using "myshopify.com" instead of "admin.shopify.com" is causing a problem. 

[phongdo]

Here for your
https://github.com/Shopify/shopify-app-bridge/issues/160#issuecomment-1692738028

[pmathbliss]

I was having the same issue. I opened a ticket with their partner support. They did some update. Now, the app is no longer saying its depreciated, but now says 'This app is taking a while to load. If you are not automatically redirected, click to open the app now.' It then opens the old admin in a new tab.

[neomi-dov]

I solved the unified admin loading issue, in my case, app was not fetching the host parameter correctly due to encoded url. I decode url before fetching host and it worked for me.

var location_search_params = decodeURIComponent(location.search);

var host = new URLSearchParams(location_search_params).get("host");

console.log("host", host);

var config = {
                  apiKey: API_KEY_HERE,
                  host: host,
                  forceRedirect: true,
                };

[Vellir]

There are quite a few people experiencing this issue as you can see here: https://github.com/Shopify/shopify-app-bridge/issues/160