Explorer crash loops, 32-bit apps can't save files

May’s Patch Tuesday for Windows 11 21H2 crashed explorer.exe into an endless loop for users with shell customization apps. But the subtler and arguably worse bug was that 32-bit large-address-aware applications had intermittent file save and copy failures. Office 32-bit showed “Document not saved” errors — the kind of silent data loss that users might not notice until they try to reopen their work. Your files looked like they saved. They didn’t. Microsoft quietly documented the issue in the support article while users discovered it the hard way.