I have never heard anything like this. I have seen the weirdest of bugs, with slug cats simply not existing, and pallets just dissapearing. Yet not once have I ever heard of projectile rock vomiting. I cannot give any real answers for this... predicament, but I can give a suggestion. You may have disable all mods, then re enable them slowly one by one to see the problem. Also, if you can, can you post a video of this? I could better help if I know what it looks like (velocity, amount, ect).

I'm having this issue with a coop companion of mine as well! They were the second player, as Saint in an Artificer Campaign play-through, and it started after we updated the drone with 5P. Issues persist even when they play as Spearmaster on the campaign.

My mod list is as follows:


Vanilla Mods

• Dev Tools
  
• Expedition
  
• Jolly Co-op
  
• More Slugcats Expansion
  
• Rain World Remix

Dependencies

• Dress My Slugcat
  
• Nutils
  
• POM
  
• RegionKit

Cosmetics

• Arachnophobia Mode
  
• Bonk Rocks
  
• Chaislug
  
• Clear Water
  
• ColourYourSpears
  
• Dynamic Sleep Screens
  
• Extra Threat Themes
  
• Frigid Threat Themes
  
• Goober Cats
  
• Kill Feed
  
• MapOptions
  
• Mewnie's Pokescugs
  
• Music Announcements
  
• No More Tinnitus
  
• PebblesMark
  
• Silly Ascension Sounds
  
• Slugcat is Baba
  
• Snailcats
  
• SplitScreen Co-op
  
• Sticky HUD
  
• Superstructure Fuse Fix
  
• SusCat
  
• Sweet Dreams
  
• Unshaded Citadel
  
• Vanilla Intros
  
• Vestiges
  
• sillymaster!

Everything Else

• Add Inv to Campaign Select
  
• Aim Helper
  
• Custom Regions Support
  
• Deathcount
  
• Dev Console
  
• Diverse Shelters
  
• Emerald's Tweaks & Features
  
• Firmly Grasp It
  
• Galaxy Slugcats
  
• Guardian
  
• HP Bar
  
• Health Bars
  
• Improved Input Config
  
• Iterator Walk
  
• Keep That Away From Me
  
• Kills Add Time
  
• Less Deadly Rain
  
• Lunacy
  
• Marks of Passage
  
• Merge Fix
  
• Mouse Drag
  
• Music triggers fix
  
• OSHA Compliant Gates
  
• Pearlcat
  
• Personalizer
  
• Pullup Fix
  
• Remix Auto Restarter
  
• Revivify
  
• Room Rando Community Logic
  
• Room Randomizer
  
• SBCameraScroll
  
• Sharpener
  
• SlugBase
  
• Spearmaster Pearl Storage
  
• Staminer
  
• Stick Together
  
• ULTRAKILL Style Region Titles
  
• Warp Menu

Originally posted by JamiMyst:

I'm having this issue with a coop companion of mine as well! They were the second player, as Saint in an Artificer Campaign play-through, and it started after we updated the drone with 5P. Issues persist even when they play as Spearmaster on the campaign.

That's odd; I know my friend fixed it but I'm not sure what it was-- they don't remember either. Our suspicion is that it's Personalizer since it's been a huge troublemaker for us.

If you haven't played the new update already, you can probably turn off updates and test it. Just like, make SURE you don't update. If you've already been struck by the update then my condolences, it's fatal lmao