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For security purpose, I covered your email address. Thanks for your understanding.
According to the error message, it seems that IT admin configures a conditional access policy in organization. This policy should restrict the Device platforms for you. For more information, please refer to this article.
If this is not the reason, I want to confirm some questions with you:
Are you invited in this organization as a guest?
Does anyone else with the similar role have the same problem?
If the response is helpful, please click "Accept Answer" and upvote it.
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