The forge version does not start some mods
Try to create a server with the ice and fire mod, vampirim mod and pandora mod, but the server doesn't start them and throws a solution of a forge version that is not in Aternos.
I had the same problem in my minecraft client and I only put the forge version that I was asked for and the problem was solved, but with the server they ask me for a version that is not in aternos and the ones that are available generate problems.