Building, integrating, or customizing apps and workflows within Microsoft Teams using developer tools and APIs
Hi @Juha Koivula,
I would suggest you can clean the caches and cookies of the browser or change a browser and reopen the browser to retry sign-in. Also try to use a different network environment.
If this issue still persists, contact Microsoft support via calling a customer service phone number in your country and let them help you check if your developer tenants were created successfully.
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