If you manually add this Image type to the asset lib does the preview work ? Could it be a missing mime type ?

Does your .jpg images have the extra attribute being added ?

Hi Minesh Shah (Netcel)

  Yes, for the .jpg images also extra attribute being added . I am not sure where we have to add mime type. Can you please guide ?

 I have already added below code in the applicaiton.

    [MediaDescriptor(ExtensionString = "jpg,jpeg,jpe,ico,gif,bmp,png,tif")]
    public class GenericMedia : MediaData
    {
        // <summary>
        /// Gets or sets the description.
        /// </summary>
        public virtual string Description { get; set; }
    }

those random numbers are for cache invalidation. as they are after the question mark, they would be ignored by the browser

Hi Quan Mai

  Do you have any idea how to avoid this image cache in the custom media tab. I believe thumbinals is broken due to this random numbers.

I think problem is somewhere else. tested on my machine with Quicksilver and the thumbnails are working fine even with the cache number

Hi Quan Mai

Any way to prevent cache invalidation ? I am still not able to resolve the issue if do you have any idea please guide me,

Hi Binay

We have not had to do this and you can try 

Setting Mime Type in .Net Core in Startup.cs

public void Configure(IApplicationBuilder app)
{
    var provider = new FileExtensionContentTypeProvider();
    // Add new mappings
    provider.Mappings[".tif"] = "image/tiff";

I believe the cache invalidation issue is a red herring it should nor interfere with the request. 

If you manually upload an Image (.tif) to the asset library is the preview thumnail working ?

Minesh 

Minesh Shah (Netcel) Thank you for your reply.

I have tried a different approach and issue get resolved. I have just append the & with the image url. So instead of https://****/cms/images/782a3Kk-aj88QHguvgY5oU/?scale=tn I am using https://****/cms/images/782a3Kk-aj88QHguvgY5oU/?scale=tn& and it's working as expected.