I re-re-reinstalled Inkscape, making sure I had the 64 bit version and loaded via the “typical” setting. I can now upload squaresville! I am now going to try other files, but this is progress!
Newcircle now uploads too! Not sure what the issue was, but this is progress!
To all of you who were awesome enough to respond: The mysterious issue appears to be gone for now. I am superstitious of technogremlins, so I can’t breath a final sigh of relief but I am not likely to have a crying breakdown at the moment. You are all better than therapy!
I am off for the moment to cook dinner and get ready for D&D game night! Ravenloft watch out, my bladesinger is coming!
Thank you again, everyone. Your kindness, patience, and expertise will not be forgotten by this newbie.