Make sure you download Calamity Mod like the first image said
#Calamity Download Error
pallid frost
fading slate
floral raven
i had the same issue, i figured it out, give me a minute and ill show you
i figured out that steam was installing the mods to the wrong directory. if you find this directory, you will find the mod and be able to move it to the right place.
the location that tModLoader looks for the mods is "Home/.local/share/Terraria/tModLoader/Mods/", however the place i found them installed was in "Home/.local/share/Steam/steamapps/Workshop/Content/" and the folders named with strings of numbers are the ones which contain your mods. So for me, from the "Content" directory, i had to look in "1281930", the folders in there contained all versions of the 2 mods: "The Calamity Mod" and "The Calamity Mod Music". The versions you want ot move are the ones in the folders labeled "2025.4", as they are the most recent version of the calamity mod.
So move the 2 Mods into "Home/.local/Terraria/tModLoader/Mods/", and refresh your game.
[THIS WAS THE FIX FOR A LINUX SYSTEM, THIS MAY NOT BE THE CASE FOR ALL OPERATING SYSTEMS, BUT IT WORKED FOR ME.]
Good luck, and if you run into any issues with the fix, feel free to @ me!
copper mantle
unfortunately it would appear that they already left the server