This all sounds scarily familiar...

https://www.ubbcentral.com/forums/ubbthreads.php/topics/249949/config-file-wiped-out

https://www.ubbcentral.com/forums/ubbthreads.php/ubb/showflat/Number/247970

https://www.ubbcentral.com/forums/ubbthreads.php/topics/250713/re-config-file-rewritten-with-0-bytes