QPR Knowledge Base 2026.1

The QPR Portal IIS application pool is now configured to use .NET CLR v4, so QPR Portal works by default without the .NET Framework 3.5 Windows feature being installed.

Previously the application pool was configured for CLR v2. On a machine without .NET Framework 3.5 the IIS worker process could not preload CLR v2, the application pool was disabled after repeated failures, and QPR Portal returned HTTP 503.