I noticed a lot of people were looking for the Yufa splines recently because the old links were broken. I managed to find a working mirror and wanted to share it to save everyone the hassle of searching.
Older forum posts sometimes mention links such as http://dl2.yufa.eu/34899.ams or http://dl.yufa.eu/Yufa.ams . These addresses may no longer be active or secure, but they are worth checking as a last resort. omsi 2 yufa splines download work