Colossal Order pushed out Patch 1.6.4f1 for Cities: Skylines II on 10 November 2026. The update folds in changes tested during the recent Open Beta and lays groundwork for the upcoming Park Adventures DLC. It also brings a batch of fixes and a reworked Paradox Mods experience.
Players who subscribe to the Paradox Newsletter can now unlock a new signature building, the Grand Post Office, as a bonus for signing up.
Gameplay and Visual Fixes
On the gameplay side, the patch fixes cities accumulating too many companies without actual buildings, a bug that was dragging down performance in larger saves. The Hydroelectric Power Plant, which had stopped functioning, is working again.
Visually, trees that had growth turned off were still ageing and expanding. That’s now fixed. The UI got an update to the Coherent UI framework, a fix for the flickering game mode image in the menu, and missing translations for the Downtown Market Set. Upscaler support was bumped to DLSS 4.5, FSR 3 and XeSS 3, and the benchmark save was refreshed.
Paradox Mods Overhaul
The bigger changes land on the modding side. Paradox Mods now has a “By followed creators” tab and a featured section showing the latest uploads from creators you follow, plus a badge on their avatars. Subscribed playsets gained a “Follow latest playset version” option, and mod visibility can now be toggled straight from the Paradox Mods UI instead of the old upload panel field.
Logged-out players can finally open and manage their Playsets and Library, and creators’ shared playsets are viewable without logging in too. Colossal Order also cleaned up a long list of smaller issues: mod content failing to load on startup, playsets stuck loading, wrong playset versions showing up when shared or subscribed, a crash in the DLC dependency wizard while offline, and follower counts not updating properly, among others.
What This Means for Mod Users
If you run mods, back up your current playset before updating, since the Coherent UI framework change and the shift in how mod visibility is set could affect how some assets display or get flagged in the Mods UI. Asset creators should note that new uploads are hidden by default now and need visibility switched on manually through Paradox Mods. Anyone who relies on the Hydroelectric Power Plant mod-wise or had performance drops from bloated company counts should see a noticeable improvement after installing this patch.
Source: Steam · Image: Steam
