.wmv file can’t be opened in Windows Live Movie Maker

First time using WLMM. Created a video, then saved using the "Recommended for this project" option under "Save movie" dropdown.  A .wmv file was created (very slowly, I might add, but maybe that's normal), which plays fine in Windows Media player.  But, I can't get it to load into WLMM so I can make updates. WLMM says the file is corrupted or in a format it doesn't recognize (even though WLMM is the app that created that file). So, two questions: 1) Did I do something wrong when I saved the file (if so, what should I have done)? and 2) is there any way to bring the .wmv file into WLMM so it can be edited?