Hello,
Thank you for your reports. I could not reproduce the issue one our side.
If I understand correctly - you were playing on 1.16.1 version of the game, then updated to 1.16.2 and Vassal Contracts disappeared from your save?
Would it be possible to attach affected save here?
This issue has been ongoing ever since the 1.16.0 major "Khans of the Steppe" update. It's already been reported by other users, identified by moderators, and apparently added to the database. The initial bug report was marked as "confirmed", then subsequent ones as "duplicate", so I'm surprised that this one was marked as "needs info".
Ever since 1.16.0 I have been unable to collect taxes and levies. The ability to change vassal contracts is gone. I have about half the troops and income that I had previously.
I believe that this issue may be caused by, or at least related to, Empire-tier realms. I am playing as the Emperor of Francia and I noticed that the Mongolian Empire in my game also has about half the troops it did prior to 1.16.0. My vassals, however, as well as other lower tier realms, seem to have the same number of troops. Factions that were previously very weak, suddenly are nearly strong enough to send an ultimatum. Other users who have posted about this bug also indicated that they were playing empire-rank realms.
While the game is technically playable, in practical terms, it is broken and unplayable for all intents and purposes. I won't keep playing with half my troops, income, and without the ability to modify vassal contracts.
I hope that this issue is resolved soon. I haven't played CK3 since the release of 1.16.0. I miss it, and look forward to being able to get back to it soon.
Vanilla game, no mods.