It's configured correctly following the instructions in the manual and with the correct API information from paypal. Clicking any paypal express button from anywhere throws a runtime error that appears as follows in the log:



[table id=ctl00_MainContent_gvEvents style="WIDTH: 100%; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=5 border=0]
[tr ][td vAlign=top align=left]System.Web[/td][td vAlign=top align=left]Page.IsValid cannot be called before validation has taken place. It should be queried in the event handler for a control that has CausesValidation=True and initiated the postback, or after a call to Page.Validate.[ at System.Web.UI.Page.get_IsValid() at BVModules_Controls_PaypalExpressCheckoutButton.PaypalImageButton_Click(Object sender, ImageClickEventArgs e) at System.Web.UI.WebControls.ImageButton.OnClick(ImageClickEventArgs e) at System.Web.UI.WebControls.ImageButton.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.ImageButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) ][/td][/tr][/table]