One thing I always have to wonder when it comes to SVGs, is where were those SVGs generated and if the SVGs have other XML info that the program can't handle.
Awhile back there was a question about a RIP and SVG files and if those files were generated via Inkscape, it has to be Plain SVG, not Inkscape SVG (and the only differences is the XML markup in the file itself).
So with the above situation, I would have to wonder about the program's import filter and what it can or can't accept.
Now, it is possible that these files are also malformed in some way. If you haven't used these files in other programs, I would bring the SVG files in another program, design program. If you don't have one, get Inkscape to view it and see if those lines are still present.
Now, you can also open up the SVG file in a text editor and see what the version number is. 1.1 has been around for a very long time, but we do have 2.x now since 2016, I think that's when that standard reached RC. That could also be a source of some contention. Attached is a picture of an SVG file opened in an IDE and the version is on line 17.