[yufran]

I had the same issue. I posted this question twice to tech support. They refer me to copy usersavedsliders folder from v15 to the v17's userpresets folder. But all of the v15 presets were lost. I couldn't find them anywhere on my computer. I can't even go back to v15, because the activation token is no longer valid.

These folders can be found under (most likely under C: drive in most cases):
user/username/appdata/roaming/anthropics/

Let me know if you have any luck.