我已经安装了DNN 8的dnn.events模块的最新版本，但试图在页面中添加错误消息（例外）来显示，而不是 请帮我解决这个问题：DNN事件模块错误
--Error: Events is currently unavailable. DotNetNuke.Services.Exceptions.ModuleLoadException: Unknown server tag 'dnn:DnnComboBox'. ---> System.Web.HttpParseException: Unknown server tag 'dnn:DnnComboBox'. ---> System.Web.HttpParseException: Unknown server tag 'dnn:DnnComboBox'. ---> System.Web.HttpException: Unknown server tag 'dnn:DnnComboBox'. at System.Web.UI.TagPrefixTagNameToTypeMapper.System.Web.UI.ITagNameToTypeMapper.GetControlType(String tagName, IDictionary attribs) at System.Web.UI.MainTagNameToTypeMapper.GetControlType2(String tagName, IDictionary attribs, Boolean fAllowHtmlTags) at System.Web.UI.MainTagNameToTypeMapper.GetControlType(String tagName, IDictionary attribs, Boolean fAllowHtmlTags) at System.Web.UI.RootBuilder.GetChildControlType(String tagName, IDictionary attribs) at System.Web.UI.ControlBuilder.CreateChildBuilder(String filter, String tagName, IDictionary attribs, TemplateParser parser, ControlBuilder parentBuilder, String id, Int32 line, VirtualPath virtualPath, Type& childType, Boolean defaultProperty) at System.Web.UI.TemplateParser.ProcessBeginTag(Match match, String inputText) at System.Web.UI.TemplateParser.ParseStringInternal(String text, Encoding fileEncoding) --- End of inner exception stack trace --- at System.Web.UI.TemplateParser.ProcessException(Exception ex) at System.Web.UI.TemplateParser.ParseStringInternal(String text, Encoding fileEncoding) at System.Web.UI.TemplateParser.ParseString(String text, VirtualPath virtualPath, Encoding fileEncoding) --- End of inner exception stack trace --- at System.Web.UI.TemplateParser.ProcessException(Exception ex) at System.Web.UI.TemplateParser.ParseStringInternal(String text, Encoding fileEncoding) at System.Web.UI.TemplateParser.ParseString(String text, VirtualPath virtualPath, Encoding fileEncoding) at System.Web.UI.TemplateParser.ParseFile(String physicalPath, VirtualPath virtualPath) at System.Web.UI.TemplateParser.ParseInternal() at System.Web.UI.TemplateParser.Parse() at System.Web.Compilation.BaseTemplateBuildProvider.get_CodeCompilerType() at System.Web.Compilation.BuildProvider.GetCompilerTypeFromBuildProvider(BuildProvider buildProvider) at System.Web.Compilation.BuildProvidersCompiler.ProcessBuildProviders() at System.Web.Compilation.BuildProvidersCompiler.PerformBuild() at System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath virtualPath) at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) at System.Web.UI.TemplateControl.LoadControl(VirtualPath virtualPath) at System.Web.UI.TemplateControl.LoadControl(String virtualPath) at DotNetNuke.Modules.Events.Events.LoadModuleControl() --- End of inner exception stack trace ---