In #401, you've been talking about a recurce pack, could I know what you are talking about, because I am experiencing this issue too.

But I don't know what resource packs you are talking about?

Which stock are you trying to place?

any, it doesn't work

We need some specific names and/or a log file.

I dont know if this is the problem but a comment says

"Server resource packs go in config/immersive railroading"

Just in case put the latest.log so the people can help you more

UNU Aerotrain
2020-04-12-3.log.gz

1. This worked without doing this on another server,
2. It doesn't let me place trains EVEN if they are out of the original pack

I'm guessing you're using an Aternos server?

...Hello... ...I still need help...

UNU doesn't work like other packs on servers. You need to copy the UNU mod jar file then change the ".jar" to ".zip" Then you put that in the server's config/immersiverailroading folder.

I am! But it works on another aternos server! Just on this one it doesn't

In the log you sent, IR isn't installed on that server.