This issue is persistent across all apps on my account. They either load solid black, white or not at all.
The preview window in AI Studio runs on a *.scf.usercontent.goog domain. When it tries to fetch React from esm.sh, the browser blocks it because the requested resource (the script) lacks the Access-Control-Allow-Origin header for your specific session origin. This is why you see the “Failed to load the app. Try reloading it” error loop in the IDE.
the EXACT SAME thing hapening to me
It started to happening to me now. I am losing a lot of money, my clients are expereinciong problems. My 300 projects in google ai studio stopped working!!! Live websites are slow and wont load properly. HELP
Same. I even tried creating a new app from scratch, and same error.
It suddenly works again!
It still doesn’t work for me 
. For some reason, it keeps inserting React 19 references in the import list. When I remove it and save, then click on preview, React 19 is added back to the import list. Does anyone know why this is happening? Is there a way to prevent this? Google AI Studio help_request
Did you implement any manual changes or workarounds before the recent platform patch? I strongly suggest reverting your code to an older version and waiting briefly for the environment to stabilize.
I’ve noticed several other developers who assumed the ‘app failed to launch’ error was a bug in their own code and attempted manual patches that may now be causing conflicts with the official fix. If you’re in a similar situation, rolling back your codebase to its state from several hours ago should resolve these issues. Hope this helps!
I didn’t implement any other changes. I was able to load it yesterday, but it doesn’t work today. I thought it might have to do with studio re-adding React 19 to the import list.
It’s happening w me too
Yeah same here, all the CDN seems to not be working for some reason
Hi @Xekhai_La_Espada ,
Welcome to the Forum! We’ve pushed a fix that should resolve the problem. Please let us know if you are still experiencing any issues.
Thanks for your patience while we sorted this out!
Still doesn’t work. The app won’t load.
This is no longer an issue related to the og post. But with that said here are steps I would personally take in your situation:
download the app
extract files and then give gemini 3 (not flash) all of the files
open your browser log (press f11) - right click in the log (not directly on the text, but just outside of the line) click on “Clear log”, once its clear - refresh page and then COPY that log
give gemini the error log
pray to the ai gods it can fix it.
This has worked for me on many such cases, but beyond this point its not related to the issue we all faced yesterday. The esm.sh issue that happened yesterday is resolved and things are back online and wide-spread issues are resolved.
Hope this helps!