Trying to save a jpg file made in a different program

I have just visited the website you have used and I created and downloaded back to my computer an overlay file.  The file was in .png format with a single layer.  I was able to import it into the Organizer and open, edit and save it in the Editor without any problems.  So, I don't think it's a layers issue unless you added a layer while editing your photo.

Here is an image that I quickly created in Elements.  As you see in the gif, there are photos of a rose and a woman which have been overlayed one over the other using the transparency control for the top layer.

Now if you want me to help you create a similar overlay image in Elements 18 (which is Elements 2020), I am happy to show you how.  But it would be helpful if you gave us more details about what effect you are trying to create if it is not something like I have demonstrated here.

Does the file with the overlay have more than one layer?  And what format is it?  If you are trying to save a multi-layer file to jpeg format, you can't because a jpeg can only have one layer.

And telling us that you have received a message that says the file may be corrupt or something like that doesn't give us much opportunity to give you advice.  We need to know the exact message or, better yet, give us a screenshot of the message.