Via [url=https://steamcommunity.com/games/TF2/announcements/detail/3298348314778996109]the Steam Community[/url]:

[quote=Valve]- Fixed a client crash related to the Ghoulpit contract
- Fixed Sinthetic contract objective counting pumpkin bomb kills instead of killing the Toastmaster
- Fixed Horsemann's Hack unusual effect not being visible in bright areas and optimized the particle count
- Fixed the hook's self-ilummination for The Hook, Line, and Thinker
- Fixed a materials problem with the Cabinet Mann
- Fixed a clipping problem with The Imp's Imprint
- Fixed some cosmetic cases not showing the correct skins in the Mann Co. Catalog
- Fixed sound file references for the Taunt: Luxury Lounge pointing to missing files
- Updated the Magical Mount and The Pony Express to be assisters in Pyrovision
- Updated the item_type_name values for some items
- Updated koth_sawmill_event
- Fixed RED team portal to the underworld not enabling

- Updated plr_hacksaw_event
- Adjusted prop fade distances
- Added more details across the map
- Added overlays in some spots to make Snipers more visible
- Filled the final death pit with billowing smoke
- Fixed perch spots around the map
- Fixed various displacement gaps
- Fixed z-fighting on fence props
- Fixed being able to place teleporters too close to your own spawn doors
- Fixed payload sawblade damage not being consistent
- Fixed players spawning in the overworld when the underworld race is active
- Fixed being able to use Bonk! Atomic Punch to bypass the stun speed in the underworld race
- Fixed being able to use the Phlogistinator to damage players in the underworld race (Thanks Barno and pinewabble!)
- Fixed errors caused by missing gib types for crows
- Fixed incorrect prop collisions
- Improved fire safety
- Prevented the HHH from falling into pits

- Updated ctf_crasher
- Fixed BLU flag outline not displaying properly when home
- Tweaked nag line preparation to ensure it works correctly for both teams
- Potential fix for casual mode lines still interrupting announcer despite being muted
- Potential fix for edge case where giants are not killed when dropping or capturing a flag on high-load servers
- Giant medics will no longer mirror blast jumps above certain speeds
- Fixed dispenser sometimes not properly attaching to giants
- Fixed having multiple giants for the same team at the same time

- Updated pl_sludgepit_event
- Removed spells due to an exploit where players could get out of the map
- Added cubemaps to fix weird visuals on metallic props
- Removed assets leftover from the non-Halloween version of the map

- Updated pl_hasslecastle
- Fixed invisible playerclip blocking part of the left exit door in RED's spawn room for the final cap
- Fixed exploit that allowed buildings to be built in an area that is later shut off from both teams[/quote]

Rumor has it:

- Size is ~120 MB