Revit 2020.2.9 Hotfix -

Revit 2020.2.9 hardens the DLL search order algorithm, forcing Revit to load critical libraries only from trusted system paths (e.g., the Revit installation folder) before checking network shares. 2. Cloud Worksharing & Central Model Corruption While Autodesx focuses heavily on Revit Cloud Worksharing for newer versions, Revit 2020 users often still use Revit Server or LAN-based worksharing. The 2.9 hotfix resolves a rare but devastating model corruption issue :

By patching the DLL hijacking vulnerability, Autodesk protects your network from infiltration through seemingly innocent .RVT files. By fixing the central model corruption bug, they save you from a weekend of recovery from backups. revit 2020.2.9 hotfix

Under specific, heavy-load conditions (e.g., 15+ users syncing simultaneously with complex linked DWGs), the central model’s “Model Log” would exceed a buffer limit. This resulted in error Internal Exception 0xC0000374 and effectively corrupted the central model, forcing teams to roll back to a backup from hours earlier. Revit 2020

Revit 2020 exited mainstream support on January 12, 2021, but entered until January 12, 2026. During Extended Support, Autodesk does not release new features or non-critical updates—but they do release hotfixes for critical security vulnerabilities and severe data corruption issues. This resulted in error Internal Exception 0xC0000374 and

Malicious actors could exploit how older versions of Revit loaded dynamic link libraries (.DLL files) from untrusted network paths. If a user opened a Revit project from a compromised network location or a malicious email attachment, the attacker could execute arbitrary code on the user’s machine—potentially installing ransomware or stealing BIM data.