How to fix "incomplete set of tages received from server" error

[HappyGoLucky]

I've been trying to host a forge server for a while now but no matter what i do it seems like it just refuses to work do to this error.
at the suggestion of a youtube tutorial i checked my logs and heres what i found:
 

01:10:54] [main/INFO]: Connecting to test.prisonfun.com, 25565
[01:10:55] [Netty Client IO #11/INFO]: Connected to a vanilla server. Catching up missing behaviour.
[01:10:55] [Netty Client IO #11/INFO]: [tschipp.carryon.common.handler.ListHandler:initConfigLists:282]: []
[01:10:55] [main/WARN]: WARNING: block Block{minecraft:coal_ore} added to BlockSelector exceeds max probabiltiy of 1!
[01:10:55] [main/INFO]: Environment: authHost='https://authserver.mojang.com', accountsHost='https://api.mojang.com', sessionHost='https://sessionserver.mojang.com', servicesHost='https://api.minecraftservices.com', name='PROD'
[01:10:55] [main/WARN]: Incomplete server tags, disconnecting. Missing: {minecraft:item=[botania:mystical_flowers, botania:petals/orange, botania:lens, botania:disposable, forge:ingots/elementium, forge:gems/dragonstone, botania:runes/gluttony, forge:nuggets/elementium, botania:runes/sloth, botania:special_floating_flowers, botania:double_mystical_flowers, botania:livingrock, forge:storage_blocks/manasteel, botania:floating_flowers, botania:mundane_floating_flowers, botania:petals/yellow, forge:ingots/manasteel, botania:petals/lime, botania:petals/magenta, botania:runes/spring, botania:runes/pride, botania:semi_disposable, botania:runes, botania:loonium_blacklist, botania:runes/envy, botania:petals/black, botania:runes/lust, botania:runes/water, botania:petals/light_gray, botania:petals/blue, botania:runes/summer, botania:petals/gray, botania:petals, botania:mini_flowers, botania:magnet_ring_blacklist, botania:runes/greed, forge:storage_blocks/elementium, botania:misc_special_flowers, botania:runes/mana, forge:nuggets/manasteel, botania:petals/light_blue, botania:special_flowers, botania:generating_special_flowers, forge:nuggets/terrasteel, botania:functional_special_flowers, botania:runes/fire, botania:petals/pink, forge:dusts/mana, forge:gems/mana_diamond, botania:terra_pick_blacklist, botania:petals/brown, botania:burst_viewers, botania:runes/winter, botania:petals/purple, botania:livingwood, botania:runes/autumn, forge:ingots/terrasteel, botania:runes/earth, botania:runes/air, botania:runes/wrath, botania:contributor_headflowers, forge:storage_blocks/terrasteel, botania:rods, botania:petals/green, botania:petals/cyan, botania:petals/red, botania:petals/white], minecraft:fluid=[decorative_blocks:thatch], minecraft:entity_type=[botania:shaded_mesa_blacklist, botania:cocoon/rare, botania:cocoon/common_aquatic, botania:cocoon/rare_aquatic, botania:cocoon/common]}
[01:11:14] [main/INFO]: Stopping!

this is the only log that doesnt host my personal IP, all of the other error messages are identical.

from what i can gather it seems like i really do have incomplete server tags, but i also dont know what that means or how to complete them.

ps, that "connecting to a vanilla server" blip comes up when i connect to my modded server too

[HappyGoLucky]

Ive tried reinstalling botania on both client and server side but that hasnt worked.

I'm taking a closer look at the logs of the server and i think i found something here.
there's hundreds of lines of errors failing to generate everything in the world from regular mobs to modded terrain and structures.
is the server trying to launch in vanilla or something? or is it somehow not able to read the mods installed into it even though they've been installed properly?
i'll paste a few:

[07:01:23 INFO]: Preparing level "world"
[07:01:23 INFO]: Preparing start region for dimension minecraft:overworld
[07:01:24 ERROR]: Unknown structure start: tconstruct:clay_island
[07:01:24 ERROR]: Unknown structure start: better stronghold
[07:01:24 ERROR]: Unknown structure start: tconstruct:overworld_slime_island
[07:01:24 ERROR]: Unknown structure start: forbidden_arcanus:nipa
[07:01:24 ERROR]: Unknown structure start: quark:big_dungeon
[07:01:24 ERROR]: Unknown structure start: tconstruct:clay_island
[07:01:24 ERROR]: Unknown structure start: better stronghold
[07:01:24 ERROR]: Unknown structure start: tconstruct:overworld_slime_island
[07:01:24 ERROR]: Unknown structure start: forbidden_arcanus:nipa
[07:01:24 ERROR]: Unknown structure start: quark:big_dungeon
[07:01:24 ERROR]: Unknown structure start: tconstruct:clay_island
[07:01:24 ERROR]: Unknown structure start: better stronghold

 just hundreds and hundreds of lines of this

ALSO:
i feel stupid for not thinking to mention this until now but its a 1.16.5 modpack

Edited February 13, 2023 by HappyGoLucky
more relavent info

[ChampionAsh5357]

The version you are using is no longer supported on this forum.

Please update to a modern version of Minecraft to receive support.

Currently supported versions are 1.19.3 (Latest), 1.19.2, and 1.18.2 (LTS).