https://www.curseforge.com/minecraft/mc-mods/easy-mob-farm

For some reason, the spider Mob is not catchable with a small urn.

Also, on a side note, curseforge is being weird with the latest version of this mod, it think the version released in august is the most up to date version, not the one released in October. I had the spider catching issue in both versions.

Animal / Monster

Hostile Monster
-minecraft:spider

I assume that the spider entry is missing in your config file.

I adjusted the config file in the latest version, so the easiest way would be to delete the existing config so that the new config get's automatically created by the next start.

If this is still not working, please attach your config file here, so that I could take another look. Thanks

I assume that the spider entry is missing in your config file.

I adjusted the config file in the latest version, so the easiest way would be to delete the existing config so that the new config get's automatically created by the next start.

If this is still not working, please attach your config file here, so that I could take another look. Thanks

I deleted the config, but I'm still having the same issue.
I tried to attach it, but it says it doesn't support that file type.

Ok, please open the config file in a text editor and check if the spider is included in the following part:

["Urn small (Mob Catching Item)"]
	#Defines the luck of capturing the mob e.g. luck of 3 means a change of 1 to 3 to capture a mob. Higher numbers requires more luck. 0 = disable luck.
	#Range: 0 ~ 100
	urnSmallMobCatchingLuck = 3
	#Catchable mobs with the urn small.
	urnSmallMobs = ["minecraft:cave_spider", "minecraft:creeper", "minecraft:spider", "minecraft:skeleton", "minecraft:husk", "minecraft:zombie", "minecraft:zombie_villager"]

If not please stop the game, add the spider entry, save the file and start the game.
If this is still not working please answer the following questions:

• Gets the item usage decrease after every try ?
• Do you use any specific mod pack or mods ?
• Do you see the same issue with cave spiders or any other mobs