总结:

您正在通过SAML颁发者使用本地帐户登录.这使登录过程发生在Azure AD B2C登录页面上.您看到的错误消息只是常规的验证错误消息.所有这些都发生在登录页面上，而不是错误页面上.错误内容仅在未处理的异常中断用户旅程的执行时由引擎使用.常规登录不是这种情况.

You are using local account sign-in with SAML issuer. This makes sign-in process happen on Azure AD B2C sign-in page. The error messages you see are just regular validation error messages. This all happens on the sign-in page, not the error page. Error content is only used by the engine when an unhandled exception breaks the execution of the user journey. Which is not the case with a regular sign-in.

您用于自定义验证错误的选项仅限于在登录页面上使用纯CSS.

Your option to customize validation errors are limited to using pure CSS on the sign-in page.

一个非常复杂的定制是在这里演示

A really complex customization is demonstrated here

通常描述UI定制的文档为

The document describing UI customization in general, is here

和使用自定义策略的UI自定义

And UI customization using custom policy here

我们将尽最大努力提供一些类似以下的错误消息:

At your best effort you will come with some nice error messages like these: