Internal Server Error but it doesnt make sense

so recently me and some of my friends started a modded server with the mod pack: All The Magic Spellbound, we downloaded it in curseforge

it worked fine for 1 day and then one of my friends got the error: Internal Server Error , so we found that its about the mods installed not matching the mods on the server but he could play in the server all morning and suddenly he couldnt, we check and he has all the mods that are supposed to be in this modpack he even reinstalled the modpack in curse forge and checked the mods again and it was the same.

we decided to switch servers so i opened the next server and it worked again but after some time i got the same problem my friend got "Internal Server Error" he can now play in the server and i cant

i checked the mods and didnt find the problem for some reason we can play on certain servers and in some we cant and it just doesnt make sense to me

i wanted to know if the problem is with the modpack or the curseforge itself or aternos servers in general

here's the server log if it helps: https://mclo.gs/yomhKRy

thank you

Quote from Roman

What makes you think it's because of a different mod collection?

"Internal Server Error" usually the result of a bug in a mod and that something is broken.

Which player had the Internal Server Error issue in that log?

i thought it was a different mod collection due to what we found on the internet, i could be wrong
if you know why this error occurs to certain players in certain servers i would like to know anything that would help

the player WODOBOGO had the problem, the log could be a wrong one though ill send another one if needed

the problem is that the player who has this error (in our case at least) cant join the server
thank you for the help

Quote from Roman

The next time this happens share the log afterwards and name us the player that had this issue.

the player WODOBOGO had the problem

heres the server log couple seconds after: https://mclo.gs/IRiL6oX

Quote from Roman

Try removing The Abyss II

Create a backup beforehand

ill try thanks