System.ArgumentNullException in ResourceManager.GetString internals
My code: System.Resources.ResourceManager resourceManager = GetResourceManager(); string str = resourceManager.GetString("delete", new CultureInfo(1033)); In current project compiled under .NET 2.0 everything works as excepted. Variable str contains resource string for LCID 1033 - Delete , this is ok. We are now upgrading to .NET 4.0, recompiled project under target framework .NET 4.0. Now compiled as .NET 4.0 assemblies, it throws exception System.ArgumentNullException with message Value cannot be null. .Stack trace: at System.Threading.Monitor.Enter(Object obj) at System.Resources