Score not opening

I opened musescore to work on a project I had started, but when the select a score menu came up the file was not there. I went to file > open and the score was not anywhere in my files even though I am sure that I saved it. When I went to file > open recent the score showed up, but when I tried to click on it it said "cannot read file: unknown type" This is on Musescore for chromebook, does anyone know what's going on?