Question: I have PSE13 on Mac OS El capitan. Yesterday it would not import photo files from either of my SD cards or from a file on my computer. Kept saying import failed, Help!

?  I have Elements 13 on a Mac computer with OS El capitan.  Yesterday when trying to import photos off of an SD card Elements said import failed.  Used another SD card same thing, tried to import a photo file from computer also import failed.  Re formated my SD cards same thing.  Has never happened before, though the program has been getting slower and beachballs a lot.  Help!!