up/down script "unable to fork"

[rfdarter]

I tried to set up a up and down script, but whenever i add the lines

script-security 2
up "/etc/openvpn/client/up-lte-wald.sh"

to my config, starting the service fails with that message

Nov 25 22:29:53 openvpn-client openvpn[399]: openvpn_execve: unable to fork: Resource temporarily unavailable (errno=11)
Nov 25 22:29:53 openvpn-client openvpn[399]: Exiting due to fatal error

my `up-lte-wald.sh` looks like this
chmod 777 and chmod +x was applied to the file

#!/bin/sh

echo "nur ein test"​

I allready modified `LimitNPROC` in `/lib/systemd/system/openvpn@.service` and set it to 1000