After installation - Failed to start thread

I have rented a server from Strato, I want to install openHab on it. I have tried it once via APT Packges and after a reinstallation via the manual way using this guide: Download openHAB | openHAB

I can not reach the website with the installation via the APT package http://server.by.strato.com:8080. In the info of OpenHab it says 127.0.0.1:8080 as URL.

With the manual installation I get the following error:

sudo su -s /bin/bash -c '/opt/openhab/start.sh' openhab
Launching the openHAB runtime...
[1,180s][warning][os,thread] Failed to start thread - pthread_create failed (EAGAIN) for attributes: stacksize: 1024k, guardsize: 0k, detached.
Error initializing container.
[1,205s][warning][os,thread] Failed to start thread - pthread_create failed (EAGAIN) for attributes: stacksize: 1024k, guardsize: 0k, detached.

Can you help me?

Can’t directly help you with that, but i want to share some concerns.
Why would you want to have openHAB running on a public server?
Without any additional measures, anybody can connect to it. For me that would be critical.