Since PanelBar for ASP.NET ships with support for ASP.NET 1.x through 4.6 using different assemblies, it is possible to confuse these files. In order to determine which version of the .NET Framework an assembly is targeted for, you can view the properties of the DLL in Windows Explorer (select the "Version" tab and view the "Comments" field).

Newer versions of Windows cannot display this field, but this information can also be programmatically retrieved by:

1. Using PowerShell to display this information, for example:

PS C:\> (dir "C:\MyDLLs\Coalesys.PanelBar.dll").VersionInfo.Comments
Designed for ASP.NET 4.6, or

2. Rendering the PanelBar.About property to your page.