Mods work completely fine on survival, but on the server they won't, here is the only info I got
java.io.IOException: Controlador no válido
at java.io.FileInputStream.readBytes(Native Method) ~[?:1.8.0_261]
at java.io.FileInputStream.read(Unknown Source) ~[?:1.8.0_261]
at java.io.BufferedInputStream.read1(Unknown Source) ~[?:1.8.0_261]
at java.io.BufferedInputStream.read(Unknown Source) ~[?:1.8.0_261]
at sun.nio.cs.StreamDecoder.readBytes(Unknown Source) ~[?:1.8.0_261]
at sun.nio.cs.StreamDecoder.implRead(Unknown Source) ~[?:1.8.0_261]
at sun.nio.cs.StreamDecoder.read(Unknown Source) ~[?:1.8.0_261]
at java.io.InputStreamReader.read(Unknown Source) ~[?:1.8.0_261]
at java.io.BufferedReader.fill(Unknown Source) ~[?:1.8.0_261]
at java.io.BufferedReader.readLine(Unknown Source) ~[?:1.8.0_261]
at java.io.BufferedReader.readLine(Unknown Source) ~[?:1.8.0_261]
at nz$2.run(SourceFile:100) [minecraft_server.1.12.2.jar:?]