After monthly patching, a large number of users who are logged onto the network report that application links from a company's intranet site, which previously opened directly into the website, are…

Single Sign-On (SSO) issues are the most likely cause, as SSO allows users to access multiple applications with one set of credentials without re-authenticating. If a patch broke the SSO integration, applications that previously relied on it would now revert to prompting for individual logins.

Password expiration would typically affect all logins across the network and alert users directly, not just specific application links on an intranet.

Account lockout would prevent users from logging in anywhere, not just prompt for specific application logins, and is usually accompanied by a lockout message.

Certificate expiration typically causes browser warnings about untrusted connections or outright connection failures, not an application-specific prompt for logon information, especially when applications are confirmed to be working properly.