@Joe5D46 Do you think this is an image from Adobe Stock? It looks to be a US Department of Defense asset, which means it has been released to the public domain, or at least there is a full size file accessible for free from their database here: U.S. soldiers retire the command colors during the ceremony marking the end of the U.S. military mis...
Here is a screenshot of the photo's metadata:
If the image is editorial it would not be royalty-free and you would not have gotten it from Adobe Stock in 2015 as we didn't sell editorial content until later. I do see images similar to this one in our Editorial collection.
We cannot offer legal advice, I think you know the answer either way.
I know these were images I got on a royalty-free website, but can't find proof of it.
That's bad because it means you cannot prove that you properly licensed the picture. In all cases, I would suggest consulting a lawyer specialized in this matter. Copyright cases can be costly if handled the bad way.
Tip: you may find more info in the metadata of the original file.
In the future, I would recommend keeping a copy of the licensing terms of any picture you may license with the original file.
The picture @Jain Lemos shows is slightly different. It may well be that the DoD released that specific picture into the public domain, but that your picture has been entered in the Reuters database. And probably, it can only be used in an editorial sense, which also means that you would have needed to acknowledge the source. All stock agencies have similar rules in this matter.