dataserializer 1.12.2 not found

[Benzeel]

So I use aternos to run my server and I have a lot of mids for 1.12 and they all are compatible but when I tried to join my server is said what is in the image I sent, so I tried to fix it over and over even tried removing it from the save but I don't know how to and when I click yes it puts me back at the menu screen and same with no. I even tried adding and removing mods.  

Heres the game output stuff: https://pastebin.com/388nypJ1
Heres some of the server logs:  https://pastebin.com/adwJpczb

also I tried having it cracked so my friend could join but I even turned that off and it didn't even work (also I bought an account long ago (still have it and use it) so please don't ban me, I just got bored and lonely so I turned cracked on so he could join also, sorry for all the TMI)

also, I don't use the forums often so if possible dm me in discord at Benzeel#5953 and tell me that you are from this topic. (if i don't respond to replies on this topic that is)

[Benzeel]

I'm new to the forums so if I did something wrong please tell me.

also i meant to say mods not mids also sorry for typos.

Edited August 13, 2019 by Benzeel