New Post: LoadExtension error

We are using 1.7 full version. While loading extension it is throwing an error "Object reference not set to an instance of an object." in the stack trace it is showing
at DotSpatial.Controls.DefaultRequiredImports.DockManager.Activate() in g:\TeamCity\buildAgent\work\356b083ef9ef62c7\DotSpatial.Controls\DefaultRequiredImports\DockManager.cs:line 47
at DotSpatial.Controls.AppManager.ActivateAllExtensions() in g:\TeamCity\buildAgent\work\356b083ef9ef62c7\DotSpatial.Controls\AppManager.cs:line 484
at DotSpatial.Controls.AppManager.LoadExtensions() in g:\TeamCity\buildAgent\work\356b083ef9ef62c7\DotSpatial.Controls\AppManager.cs:line 410