A young person I know has made numerous images on an iOS app called Mandalas and the app allows her to save these as svg files. We then open these on my Mac and print them, only, some of these files (now nearly twenty) fail to import and when opened in finder the icon changes to a text document with these words: "This page contains the following errors:error on line 1 at column 1: Document is empty. Below is a rendering of the page up to the first error." There is nothing more on the page. We're extremely eager to fix these images as they exist in no other form. Has anyone else encountered this weirdness?
An SVG is in essence just a text file, containing code which describes paths and their properties (fill, border, etc.)
So try opening the broken files in a simple text editor like Notepad. What do you see? Is there any code in there? The file should ideally start with
<svg ....> and end with
</svg> (where .... are optional attributes like width, height and viewbox).
The error "Document is empty" seems to suggest there is no code in the SVG. In which case there is no solution except te re-export the files from the app.
An alternative would be to use an online service like SVG Viewer. Just upload the file and see what's in there. You can edit the SVG inline and see the result instantly.
My 2 cents.
First, see if you still can open the original files in the original application.
Second. If the icon changed on your mac, it seems you do not have a specific application to open SVG files. Many programs can read them, including almost any browser, but not all open them correctly. So, one option is to install Inkscape, which is, IMHO one of the programs that read and save them most reliably.
Then see if you can export it to another format before printing. You could export it to a High-resolution PNG. I do not know if the original program can.