AbleCommerce Shopping Cart Software

We recently switched the full site to HTTPS and since then, our error log has been filling up with this message:

An error has occured at https://www.firefold.com/favicon.ico
Exception: Index and length must refer to a location within the string. Parameter name: length Stack Trace: at System.String.InternalSubStringWithChecks(Int32 startIndex, Int32 length, Boolean fAlwaysCopy) at CommerceBuilder.Services.MobileDetection.IsMobileDevice(String userAgent) at CommerceBuilder.Services.MobileDetection.GetBrowserCapabilities(HttpRequest request) at System.Web.Configuration.HttpCapabilitiesBase.GetBrowserCapabilities(HttpRequest request) at System.Web.HttpRequest.get_Browser() at System.Web.Security.CookielessHelperClass.UseCookieless(HttpContext context, Boolean doRedirect, HttpCookieMode cookieMode) at System.Web.Security.FormsAuthenticationModule.ExtractTicketFromCookie(HttpContext context, String name, Boolean& cookielessTicket) at System.Web.Security.FormsAuthenticationModule.OnAuthenticate(FormsAuthenticationEventArgs e) at System.Web.Security.FormsAuthenticationModule.OnEnter(Object source, EventArgs eventArgs) at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

The favicon appears to be working properly. Any idea what might be causing this?

Which version of Gold is this ? There was an issue with Mobile Detection logic similar to this which was fixed a while ago. The issue which was fixed due to empty user agent.

AbleCommerce Gold (build 5731)

[AC8-2517] - null key exception when user agent is null

This was fixed in Gold R8. It was happening due to empty/null user agent.

I don't foresee us upgrading anytime soon, as we have quite a bit of customization going on. Is there a fix we can apply?

Since you mentioned about customization, do you have back end source code and customized it or they are just front end custom codes? If you are already working against back end codes for customization then I can provide you with instructions to get it fixed in source.

We have full source code and both front and back ends have customizations.

Edit CommerceBuilder.Services.MobileDetection.cs file and locate following line of code and update it like