http://msmvps.com/blogs/alvin/archive/tags/CLR+requiredruntime+version+3.5+.NET/default.aspxTags: CLR requiredruntime version 3.5 .NETenCommunityServer 2008.5 SP2 (Build: 40407.4157)http://msmvps.com/blogs/alvin/archive/2007/10/26/requiredruntime-fails-for-targetting-clr-versions.aspxFri, 26 Oct 2007 14:38:00 GMTd67277c4-116b-43f1-b688-e9ef184ea916:1265356vapordan@hotmail.com1Recently, I walked right into an ambush with .NET. A client asked how best to target a CLR version from a .NET application. Easy right? Just use this in an app.config file: &lt;startup&gt; &lt;requiredRuntimeversion=&quot;v1.0.3705&quot; safemode=&quot;true&quot;...(<a href="http://msmvps.com/blogs/alvin/archive/2007/10/26/requiredruntime-fails-for-targetting-clr-versions.aspx">read more</a>)<img src="http://msmvps.com/aggbug.aspx?PostID=1265356" width="1" height="1">CLR requiredruntime version 3.5 .NET