As mentioned in the documentation, there are limited availability of GPT-4 models in East US and France Central region and this could be preventing you from deploy a new GPT-4 model in East US.
I suggest you to please use your other GPT-4 model which is available for you at France Central. You may need to check the above documentation or check back the model availability later in East US region.
Sorry for the inconvenience this has caused you.
Please let me know if you have any other questions.
Thanks
Saurabh
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