I am trying to upload a certificate via Web Sites -> SSL -> Upload Certificate and hit this error:

[2/24/2017 1:04:48 AM] ERROR: SSLModuleService could not add new X.509 certificate to ‘abc.com’ web site. All changes have been rolled back.
System.Runtime.InteropServices.COMException (0x800700B7): Filename:
Error: Cannot add duplicate collection entry of type ‘binding’ with combined key attributes ‘protocol, bindingInformation’ respectively set to ‘https,’
at Microsoft.Web.Administration.Interop.IAppHostElementCollection.AddElement(IAppHostElement pElement, Int32 cPosition)
at Microsoft.Web.Administration.ConfigurationElementCollectionBase`1.Add(T element)
at Microsoft.Web.Administration.BindingCollection.Add(Binding binding)
at SolidCP.Providers.Web.Iis.SSLModuleService100.AddBinding(X509Certificate2 certificate, WebSite website)
at SolidCP.Providers.Web.Iis.SSLModuleService100.InstallPfx(Byte[] certificate, String password, WebSite website)

I cannot seem to find a duplicate entry in IIS. Any ideas?