AbleCommerce Shopping Cart Software

[MissingMethodException: Method not found: 'System.String CommerceBuilder.Utility.StringHelper.Replace(System.String, System.String, System.String, System.StringComparison)'.]
CommerceBuilder.Payments.Providers.GoogleCheckout.GoogleCheckout.BuildConfigForm(Control parentControl) +0
ASP.admin_payment_addgateway2_aspx.Page_Init(Object sender, EventArgs e) +79
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +15
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +33
System.Web.UI.Control.OnInit(EventArgs e) +99
System.Web.UI.Page.OnInit(EventArgs e) +9
System.Web.UI.Control.InitRecursive(Control namingContainer) +321
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +834

What could cause this? It seems to be part of CommerceBuilder.dll

Judy

What is your application version? What made this error to appear, I am asking about the action that resulted it? Finally do you have any customization?

Lots of customization, but not in admin.
I went to 'Edit Gateways', then 'Add Gateway', then 'Google Checkout'.

Version is 7.0.

It looks like the file CommerceBuilder.GoogleCheckout.DLL comes from a newer version than the file CommerceBuilder.DLL. If you went to Help -> About, the text box would show version numbers for all of your DLL files. Posting that content might be helpful.