In Global.asax.cs :
⚠️ : Version 1.2.10.0 does not support .NET Core or .NET 5+ natively. It targets .NET Framework 1.1, 2.0, 3.5, and 4.0. For modern .NET (Core/5+), use log4net 2.0.x or later.
: Required by Crystal Reports, but technically incompatible with the official one because the signatures didn't match. The Common "Horror" Scenario A developer would try to use a modern library (like a newer version of NHibernate or an internal tool) that required a newer version of log4net. Upon running the app, it would crash with the dreaded: "Could not load file or assembly 'log4net, Version=1.2.10.0... The located assembly's manifest definition does not match the assembly reference." This happened because the .NET runtime couldn't decide which "version 1.2.10.0" to trust—the one the developer installed or the one Crystal Reports secretly needed. The Resolution (How to fix it) If you are encountering this today, the "helpful" part of the story is the solution: Binding Redirects
