i do have optifine on so ... there is that
specifically an iron door with a button
malisisdoors-1.12.2-7.2.3
Forge: 2587

https://pastebin.com/NBVRZNVx

bra im using ftb i wish :P ill be of more help once i get my 3000$ server made :P but if u got any ideas on the cause that would be nice

Can you try again using latest MalisisDoors version ?
If it still happens, can you try with that MalisisCore version : https://oss.sonatype.org/content/repositories/snapshots/net/malisis/malisiscore/1.12.2-6.3.3-SNAPSHOT/malisiscore-1.12.2-6.3.3-20180115.163150-2.jar ?
Please type /malisis debug syncer in chat and post the client and server log output (with the new core version).

Nothing prevents you to manually replace mods in the folder I think.

will it let me connect ? i think all forge does is check the version are the same? i can cuz i use my own launcher. hold on ill try

I don't do version version checks, but the new jars should also be on the server. If the server has a different version, there will be issues.

ya it wouldn't let me join :/ but the server owner might make a dev server to see if it is fixed
give me a few days ;p

First of all remove optifine