Profile: GeorgiaBril

Hello. I am running nopcommerce v4.00 with the Nop ArtFactory Responsive Theme.

My log is full of the same error:
Short message: Object reference not set to an instance of an object.
Full message:
System.NullReferenceException: Object reference not set to an instance of an object.
   at SevenSpikes.Nop.Plugins.ProductRibbons.Controllers.ProductRibbonsController.RetrieveProductRibbons(ProductRibbonsInfoModel model)
   at lambda_method(Closure , Object , Object[] )

IP address: 66.249.66.157
Customer: builtin@search_engine_record.com
Page URL: https://www.annassecret.gr/ProductRibbons/RetrieveProductRibbons

I get this error constantly: 780 times already today and it is not yet noon!

Do you have any idea why this is happening and what can I do to avoid it? I get frequent (one every 3 or 4 days) crashes of he application and I must restart the IIS worker to get it back working. Note sure that these errors cause the crash, but it is a possibility.

Thank you in advance,
Kyriakos