我在Azure B2C中创建了一个策略，下载了该策略并进行了一些自定义。当我尝试上载它时，出现了我不理解的这些继承错误。即使没有进行任何更改，我也会遇到相同的错误，只是尝试上传刚刚下载的策略。这个错误指的是什么？为什么只用上传的策略不覆盖该策略？
Unable to upload policy. Reason : Validation failed: 1 validation error(s) found in policy "B2C_1A_B2C_1_SIGNIN" of tenant "m60b2c.onmicrosoft.com".Policy 'B2C_1A_B2C_1_Signin' of tenant 'm60b2c.onmicrosoft.com' is not allowed to inherit from the specified base policy. Inheritance chain: {
"TenantId": "m60b2c.onmicrosoft.com",
"PolicyId": "B2C_1_Signin",
"TenantObjectId": "fb3c2543-8e76-443a-bf5d-4f14f78dbb9b",
"Root": true,
"Derived": {
"TenantId": "m60b2c.onmicrosoft.com",
"PolicyId": "B2C_1A_B2C_1_Signin",
"TenantObjectId": "fb3c2543-8e76-443a-bf5d-4f14f78dbb9b",
"Rule": "All",
"InheritanceAllowed": false,
"Reason": "Policy 'B2C_1A_B2C_1_Signin' in tenant 'fb3c2543-8e76-443a-bf5d-4f14f78dbb9b' is blocked from inheriting policies from 'b6291105-4814-4453-831c-7aba93c480b2' as the basic policy constraint handler 'B2CBasicPoliciesOnly' cannot match the policy id to a prefix or registered policy id."
}
}