You are likely missing the 64bit version of Java. It's either not installed or needs reinstalling.
Want to check if it's installed? Open a command prompt and type:
java -d64 -version
If it gives you an error, you don't have it installed. You can download it here.
As the server owner, try connecting with "localhost" (without the ""). Works? Great! This means there is nothing wrong with the actual server.
However if you want other people to be able to play on your server, you will need to port forward your ip. See section on Port forwarding.
No unfortunately there isn't a version for mac. Mcss is Windows only.
Supported OSs: Windows Server (2008R2 SP1/2012/2016), Windows 7, 8 and 10
No, it's software that runs on your computer.
Nothing like Aternos.
Do you have .NET Framework 4.7.2 (or higher) installed?
Your performance counters are corrupt.
To rebuild them, open a command prompt with administrator rights and execute the following commands:
(if the lodctr command fails, simply run it again ^^)
Yes that is completely normal, that is called an IPv6 address. Most people don't have access to IPv6 yet so it's smart to share your IPv4 address instead.
(examples) There are 2 versions of the IP protocol.
More info about IPv6
For a while (before August 2019) the server template had a fault in it. The following steps will guide you in correcting this:
That's it, done.
There was an issue with the old api returning incorrect info, resulting in a caching issue.
Exit out of mcss and delete the
/resources/cache/updates folder. Start mcss again and the update will succeed.
Due to backend api changes version 10.4.0.0 (and older) was considered End of Life (EOL) as of January 1st 2020. Update from these old builds is no longer possible, they might even break.
You will need to update mcss manually. Download the latest version from the website and rename it to mcss.exe and copy'n replace it with the existing one. (make a backup just in case)