We added the QwickOrderEntry module to the BuyNow page and get a server error whenever we hit the page.

This is in the Event Log.

DNN 5.63, Smthcart 4.48.

 System.Exception: Unhandled Error: ---> DotNetNuke.Services.Exceptions.PageLoadException: Can't get ModuleId for given module name 'Smith.BuyNow' ---> System.ApplicationException: Can't get ModuleId for given module name 'Smith.BuyNow' at Smith.DNN.Modules.BuyNow.MyToolBox.GetModuleIdByName(Int32 tabId, String moduleName) at Smith.DNN.Modules.BuyNow.MyToolBox.GetSmithSettingString(Int32 buyNowTabID, String smithSetting) at Smith.DNN.Modules.QuickOrderEntry.QuickOrderEntry.Page_Load(Object sender, EventArgs e) at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) at System.Web.UI.Control.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace --- at DotNetNuke.Services.Exceptions.Exceptions.ProcessPageLoadException(Exception exc, String URL) at DotNetNuke.Framework.PageBase.OnError(EventArgs e) at System.Web.UI.Page.HandleError(Exception e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest() at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) at System.Web.UI.Page.ProcessRequest(HttpContext context) at ASP.default_aspx.ProcessRequest(HttpContext context) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) --- End of inner exception stack trace ---
 

You need to set the location of the BuyNow module in the settings for the QuickEntry Module.

Willing to bet it's empty in the settings. When you add new Smith Modules they have to be linked.