I have checked the website, but there is no available information about this error. I have also installed it on my PC and added 500 fonts, and the application ran normally. Remove the current version, even if it's the latest one, then re-download it using the official one and install the program on another partition. Make sure that you install it on a NTFS partition.
Also, contact the developer JungHoon Noh at https://about.me/xiles (press the Email Me button).