Below is helpful troubleshooting information if you've having problems updating the TD-50 to its latest version.
First check the SD card that you're using for the update/upgrade process. The TD-50 will support SD card sizes up to 32GB only. Larger SD cards are not supported.
If it's a compatible size, format the SD card within the computer first using the FAT 32 registration, then insert it back into the TD-50 and format it within the TD-50.
If the format process completes without an error message, eject it and then insert it back into the computer.
It's important to transfer/copy the update files correctly to the SD card. Before they are transferred, they must be uncompressed (unzipped).
Next, be sure to transfer all needed files ( e.g. UPA.bin, exec.bin, and Wave folder) to the "root directory" (upper most level) on the SD card. Do not place them inside any folders on the card. Once they have been copied, you should see the .bin file(s), wave folder, and Roland folder in the same window.
You can then eject the card from your computer, insert it back into the TD-50 and proceed with the upgrade process.