I tried export/import and got this...
DotNetNuke.Services.Exceptions.PageLoadException: Multiple controls with the same ID 'QuestionPanel_97d95224-fe39-44ab-8f7b-0681dade06dc' were found. FindControl requires that controls have unique IDs. ---> System.Web.HttpException: Multiple controls with the same ID 'QuestionPanel_97d95224-fe39-44ab-8f7b-0681dade06dc' were found. FindControl requires that controls have unique IDs. at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FillNamedControlsTable(Control namingContainer, ControlCollection controls) at System.Web.UI.Control.FindControl(String id, Int32 pathOffset) at System.Web.UI.Control.FindControl(String id) at System.Web.UI.WebControls.BaseValidator.CheckControlValidationProperty(String name, String propertyName) at System.Web.UI.WebControls.BaseValidator.ControlPropertiesValid() at System.Web.UI.WebControls.BaseValidator.OnPreRender(EventArgs e) at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace ---