Trying to Burn Disc Image to DVD-"Nothing To Record" ?

[CaptainGoffy 0]

I have Toast 11 and a Mac running High Sierra. 

I want burn a .toast disc image to DVD. It shows up on my desktop thus 

It also appears in my files at 4.36 GB

When I drag it into Toast it tells me NOTHING TO RECORD ??

 

ANYBODY FIGURE THAT ONE OUT PLEASE?  I can view it in DVD player, I can play it through and if I explore the folders  it shows it has all the contents I know it has, but burning it to DVD via this tried and tested route suddenly does not work. IDEAS ?

 

Edited May 11 by CaptainGoffy
2 identical images

[CaptainGoffy 0]

My solution was to burn this image using the Mac's BURN software ! Right click on the Disc Image icon and choose the option "Burn to disc"-so I used Toast to create it but Burn to burn it....