The modloader install is incomplete
Applies to Forge, NeoForge.
What it looks like in your log
Error: could not open 'libraries/net/neoforged/neoforge/21.1.72/unix_args.txt'
What causes it
Modern Forge and NeoForge servers start through generated argument files. A missing unix_args.txt or user_jvm_args.txt means the installer never finished, or the start command runs from the wrong directory.
How to fix it
Run the loader installer again with --installServer in the server directory, then start via the generated run script. Java 17 or 21 is required depending on the Minecraft version.
Not sure this is your problem? Paste your log and Roastd will tell you which of these it actually matched, and what else it found.
Check your own log