Kurt

I have had this problem only once with new version how ever i was not on top meaning i didn't have to move for a head smash.. it like they fall backwards and then stumble forwards. as the hit the ground... yet. I watched your vids crazy.  a slight improvement.

I didnt want to take eyes of this thread and just wanted to tell the mods all the issues i had have been resolved since the updates. 

After constant playthrough as i have had time. I have not encountered the missing swing issue again, in fact it seems to have gotten slightly better? maybe i had a bad day or something i don't know.

Further consideration i have encountered regarding zombies being push in corners or next to walls and the funny zombie falling animation.

Most of the issue is caused when being pushed. there's something when they hit the floor on rare occasions that makes then stand up on 2 feet when they shout be on the floor.

an idea - To maybe solve and give a more dynamic approach to a zombie killing method. Your could push zombies against walls. Just like how they hug them when they see you. In the temporary dazed state you can execute a insta weapon kill or a weapon less head smashed or smash through glass. in multi combat. they either die due to low hp or high hit depending on weapon instakill stats or fall backwards on the floor to get back up.

In my head this may solve a few wall issues i have encountered over the last days.

Loving the updates and love the hard work the team is putting into this game. The sounds are ...... juicy

Thank you for your time
Kurt

This is a known issue that has reappeared recently. We're aware and are working on fixing it. Again.  

41.55 Patch
 
NEW

- Added new 3D items + fixed some.
- Added a context menu for choosing which CD/VHS to insert into the device (when using a controller)
- Display CDs and VHS tapes in the Training Materials UI
- Updated main-menu credits.
- Updated community translations.

ANIMS
- Changed climb fence success anim to a quicker finish  
- Tweaked climb fence fail  
- Shaved off a few frames from Bob/Bob_StaggerBack_3m  
- Adjusted Bob_AttackPistolWhip02.X to same length as shoves  
- Tweaked head of Bob_WalkBwdAimHandgun.X to better blend with other anims  
- Shaved off some frames from Bob_StaggerForward.X  

MODDING

- Added optional vehicle.passenger.showPassenger=true|false parameter for iBrRus.
 When true, the player model isn't hidden when entering, exiting or sitting in that particular seat.

BALANCE

- Player running through a horde will now have greater chance of falling
- Full helmets less likely to fall from zombies attacks.
- Gave vehicles more engine force in first gear.

TRANSLATIONS

- Added translations for Boredom/Stress/etc notification text above the player's head.
- small delay when switching cd/tape on/off
- bzzt-fzzt and zap sound when switching on tape

SOUNDS

- re-balanced the whole reverb/direct signal mix
- tweaked the music volumes of individual tracks a bit (though there might still be more minute things to tweak)
- adjusted player and zombie footstep loudness 
- new scratch lacerate and bite assets with mix adjustments to make them stand out more
- new window thump sounds with 70% chance of additional window "squeak" layer
- first set of new door thumps, we're planning to add a condition parameter to change the sound based on door condition
- some mix adjustments to wind/rain 
- added some fake occlusion for the zombie voices based on their character inside / outside states relative to the players inside outside state until the occlusion system rework
- adjusted balance of finish sound to make them pop out more
- "fixed" the timing issue of the stomp -> head smash delay by delaying the stomp sounds 200ms in general
- turned down drink from sink sound, that was too loud
- fixed the glass breaking sound being too low
- adjusted ambient bed mix to reduce general air backdrop loudness
- made birds / wildlife a bit more sparse
- tweaked the standard car engine a bit
- reduced the volume of the car damage layer
- Added multistagebuild.CompletionSound, the sound that plays when a wall is upgraded.
- minor tweaks and balance
- Fixed some ambient sounds being controlled by the Sound Volume slider instead of the Ambient Volume slider.
- Play the Painting sound when painting signs.
- Added optional ISBuildingObject.completionSound which plays when finishing a carpentry or metalwork action.
- Allow a food item's CustomEatSound script parameter to be an empty string to play no sound instead of the default eating sound.
 This can be used when the animation will play a sound at the right time, instead of starting the sound at the beginning of the action.
- Smoking cigarettes plays the Smoke sound once during each animation loop.
- Updated scripts with BuildMetalStructureXXX and BuildWoodenStructureXXX sounds (they are not implemented yet).
- Play a breaking-object sound when picking up furniture fails.

FIXES

- Fixed hotdrink not working with some mug + double recipes. (Reminder: you need a mug with water to start a hot drink)
- Fixed the selected container in the Loot window changing due to the player turning while transferring items.
- Fixed untranslated Perk names in halo text when a new level is attained.
- Fixed endurance not being drained due to running during "Walk To" movement (or any automatic movement).
- Fixed Lua error trying to play a CD/VHS with the controller.
- Fixed the hotbar remaining hidden after unplugging player #1's controller and reverting to keyboard and mouse.
- Fixed (hopefully) random textures appearing when displaying corpses for the first time.
- Fixed a Lua error with commit 7143 "Fixed the selected container in the Loot window changing"
- Fixed auto-zoom while in a vehicle not respecting the enabled Display zoom options.
- Fixed attaching trailers to vehicles that were removed from the world after being replaced by smashed versions.
- Fixed missing comma in FertilizerEmpty item script.
- Fixed collision properties of stair pillars not being set properly after constructing stairs.
- Fixed "Index -1 out of bounds for length 8" exception in FliesSound due to negative z corpse coordinates.
- Fixed the position of the rotate-item prompt in splitscreen.
- Fixed IsoStove.doSound() exception that happens when a running stove is destroyed by fire.
- Fixed rotate-item prompt appearing when using a controller.
- Fixed the tooltip for the farming cursor and wall-upgrade cursor not being hidden after shoving.
- Fixed missing Tooltip_item_StackWeight (got lost in community-translation update).
- Fixed the Survival Guide being displayed when using a controller; it doesn't work with it currently.
- Fixed the Training Materials button overlapping other text with 3x font size and many traits.
- Fixed missing "/" characters in the Log Wall context-menu tooltip.
- Fixed crafted double-door objects losing some properties when opened (in particular, the thumpSound).
- Fixed missing Tutorial zombie noise, but temporarily using old TutorialZombie sound
- Fixed replacing roofs_accents_xxx sprites with the wrong burned-roof sprites.
- Fixed the Smash Window action being immediately cancelled due to the controller B button being pressed.
- Fixed displaying a context menu of CD/VHS choices when dragging an item to the Device Options window. It is only needed when using a controller.
- Fixed being unable to wash a single bandage in a bag (it wasn't transferred to main inventory first).
- Fixed Joypad tutorial
- Fixed various aspects of tutorial where people were going wrong
- Fixed inventory pane no longer stuck open after nullify mouse drag in tutorial
- Fixed right click menu working after nullify mouse drag in tutorial
- Fixed duplicate issue in more places, when dropping on other locations (ISInventoryPane + ISInventoryPage) in tutorial
- Fixed inventory pane no longer stuck open after nullify mouse drag in tutorial
- Fixed right click menu working after nullify mouse drag in tutorial
- Fixed bandanas providing far too much head protection
- Fixed some containers being rendered high off the ground after being moved by the player.
- Fixed zombies rotating to face the player during hit-reaction and stagger-back animations. This usually happened when hitting zombies from behind.
- Fixed zombies climbing through windows that are behind them. This sometimes happened after the player shoved a zombie into a window.
- Fixed a Lua error in the main menu after deleting the last savefile. The Continue and Load buttons were hidden but still accessible using a controller.
- Fixed some wrong calcul when doing multistage building, ending doing a lvl1 wall, upgrade to lvl2 having more health than a "pure" wall lvl2.
- Fixed placed 3D items being removed by the SandboxOptions WorldItemRemovalList 
- Fixed furniture not appearing when in a stationary car - this was caused by an optimization. Furniture will now only disappear if cars are moving at a middle-high speed.
- Fixed the "infected" flag on body parts not being set to false after a wound heals.
- Fixed an issue placing 3D items with the Double-sized Textures option turned off.
- Fixed the hotbar remaining visible after hiding all UI elements.
- Fixed item container being set to nil in some cases.
- Fixed 1-frame delay before corpse textures appear.
- Fixed the stove-running sound not stopping sometimes with two-part stoves.
- Fixed ingredients not going back to their original container when using the Crafting window.
- Fixed ingredients not going back to their original container sometimes when doing "Craft All".
- Fixed duplicate context-menu "Rest" options for tents.
- Fixed some instances of zombies turning while lying on the floor - needs further feedback.
- Fixed (hopefully) an "invalid direction" exception in BrokenFences

The error seems pretty ambiguous as it seems like the game errors out because it cannot spawn a zombie in a square as far as I understand it. That can mean basically anything as it can be tied to map mods or any mods that change anything about zombies (their behavior or clothing etc)
Best I can suggest is disabling mods and checking whether the issue gets fixed, that way you can find out which mod causes that.
As for Linux, the game should run just fine on it. Though depending on the distro there might be other issues depending on how the monitor is being handled by Linux itself and such.