Gemini API 404 Error in Google Studio App

I have build an app with Google Studio.
The app uses Gemini te do a task.
At first it worked fine.
After about 24 hours the Gemini paart sport working.
I used Gemini to ask for assistance, but I had tit go to paid support.
This is the message I have toit send.
Hello Google Support, I am trying to make a basic generateContent call to the Generative Language API from my Node.js server, using a valid API key from my project ‘RoosterplannerVA’. My project has Billing enabled. Both the “Generative Language API” and the “Vertex AI API” are Enabled. No matter which model I try (gemini-pro, gemini-1.5-pro, or gemini-1.5-flash), the API endpoint generativelanguage.googleapis.com consistently returns a 404 Not Found error. This also happens when testing in the AI Studio build. The exact error from my Node.js server log is: [404 Not Found] models/gemini-1.5-flash is not found for API version v1beta, or is not supported for generateContent. I made the app with Google Studio Ai Build. At first it worked. Later I was not able to use an AI option in the app. Pleiase hekp me getting on. This indicates a permission or policy issue on my project that I cannot see. Please investigate why my project is blocked from accessing these models. Thank you.

Hi @Govard_Slooters
404 Not Found error usually means the requested resource wasn’t found. Can you try using with latest models like Gemini 2.5 Pro or Gemini 2.5 Flash and let me know if you are still facing this issue
Thanks