Here’s a fun one. When an update to the Microsoft ODBC Driver 18 for SQL Server (18.7.1.1) lands on a site server, Configuration Manager can lose its connection to the site database.

What it looks like

  • sitecomp.exe crashes (exception c0000005), with COM+ errors (Event ID 4786) referencing msodbcsql18.dll in the Application log.
  • SMSEXEC.log fills with repeated failures to connect to SQL, and hman.log threads go quiet.

Why it happens

According to a Microsoft response in the thread, ConfigMgr ships its own older Visual C++ runtime in its install folder, and the new ODBC driver doesn’t get along with it. Updating the system-wide VC++ redistributable alone may not fix it.

Workaround

  1. Roll the ODBC driver back to 18.6.2.1 on the site server (and any other site systems that took the update).
  2. Restart the site server.
  3. Block 18.7.1.1 from re-installing until there’s a supported fix: decline it in WSUS, exclude it from your ADRs, or pause it in your third-party patching tool.

Full discussion: Latest ODBC Driver 18 for SQL (18.7.1.1) breaks SCCM site server SQL connectivity

A dependency update breaking the site server is about the most alive thing a product can do.