Photoshop elements 10 changed overnight !!
Michel's answer is a good one. Your program should have given a warning for the 16 bit to 8 bit conversion when saving. I'd like to add rules-of-thumb about "bits". A 16 bit file is a compressed file. A 8 bit file is an uncompressed file. Digital cameras utilize 16 bit files for compression (not needed today). Cameras save in 16 bit RAW in these formats: Canon has CR2 (16 bit RAW), Nikon has NEF (16 bit RAW). PSE-10 will not convert from RAW to TIFF or from 16 bit to 8 bit files until you go to save or print. In PSE you will need a plugin (converter). You may need Photoshop 6 or better which includes a plugin for RAW to TIFF, and bit-conversions. At the minimum, Photoshop 6 (a 64 bit program) will work with Windows 10. Also, a printer will want a 16 bit file converted to 8 bit for printing. PSE-10 can handle this.