Tag not monitored by Microsoft.
The error code ERROR_VUE_WIDE_BLOCK indicates that the Pearson VUE account used to schedule the AZ‑900 exam has been blocked, typically due to multiple failed payment attempts.
To resolve this and be able to register/schedule the exam again, contact Pearson VUE support so they can review the account and lift the block. Use the Pearson VUE support link provided via Microsoft Certification Support: https://aka.ms/CertificationSupport.
If further help is needed after the block is cleared (for example, if the error persists or there are other scheduling issues), open a request through Microsoft Certification Support as described in the same support page.
References: