Via HLDS:

• Updated the Case Global Unusual Effects to draw from a pool of previous years' Halloween Unusual effects during the Scream Fortress IX event. This applies to all cosmetic cases.
• Fixed all classes doing 3x damage when landing on enemies
• Fixed the Flare Contract Bonus Objective requiring mini-crit kills instead of crit kills
• Made it easier to score "defend an objective" style Contract objectives
• Lowered the requirements for the Amputator Contract's bonus objectives
• Fixed a case where players standing directly in front of the Pyro would not get burned
• Fixed a bug related to the Medi Gun and changing class/loadout while being healed
• Updated Mann vs. Machine
• Removed the "Faster recharge rate" upgrades from The Dragon's Fury
• Fixed the missing "Increased Airblast Push Force" upgrade on The Dragon's Fury

Amended from the 10/30/17 (10/31/17 UTC) update:

• Fixed the new airblast not honoring airblast vulnerability modifiers on Mann vs. Machine bots
• Fixed the new airblast not benefiting from the airblast force upgrade in Mann vs. Machine
• Fixed The Mantreads not properly granting airblast resistance