To use an external style file on the PSR-E413, you need to use the Yamaha Musicsoft Downloader to transfer the file to the keyboard's memory, then you must use the "Sff Load" function to load the style file to Style Number 156.
For the style file to be compatible with the keyboard, it must be in the SFF1 format rather than the SFF2 format. It must also have a file extension of ".STY" and the file name should not contain any additional periods or other problematic characters.
For the style file to load, it must be no larger than (if I remember correctly) approximately 50 kB, otherwise it will be too large to load.
For the style file to play properly, it should use MIDI channels 9 through 16 for the appropriate style parts, and the style sections should be encoded properly.
It's difficult to say what the problem might be without being able to examine the style file, but the following thread contains some information that might be helpful:
Last year I purchased my Yamaha E363 digital keyboard. Learned all the basics, chords progression and other techniques. Now for the first time, I tried to load external styles (downloaded from internet) but not a single one shows up in style selection section. I am using Yamaha music downloader...
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