Add mods on Prominence II

[fleet ridge]

I’m trying to play with friends on Prominence II, we added a few mods to improve the modpack, and it works fine in solo. But as soon as I click on multiplayer, the game crashes and shows the attached window.
Can anyone help me?

[dusky plover]

well no shit

you removed the core mod

[somber nacelle]

do not remove Luna

[fleet ridge]

I don't have removed the core mod

have you another solution ?

[fleet ridge]

and if i removed prominence its doesn't work

[dusky plover]

why did you remove Luna anyway

did you add Essential?

[last crow]

Are you trying to add essential? What launcher you using?