Minecraft 1.3 FAQ - Local server, errors, black screen and single player

Jeb is working his way through the merge of SMP and single player into one unified platform. The recent snapshots (12w18a and 12w19a) contain a silent server program which runs whenever you play minecraft. We try to clear up some of the confusion and explain why you might be experiencing problems.

Do I need internet access for Single Player now that it's merged?

No, you don't need internet access for single player. When you start a single player game it will silently start the new minecraft_server.jar file which runs a background process. As you play single player you are really playing locally on your own server. Hence the reason why you can use SPC commands to view whitelist, ban players etc.

You can happily disable all network connections and still play Minecraft.

Single Player Connection refused Error

When you start a new single player game you should see..

"Connecting to Server"

..and then the game starts.

However, you might see the following error message if something went wrong:

"Connection refused: connect"

The solution to this is simple. Just remember to type your user name into the Minecraft launcher when you start the game. Since its single player and you're playing offline then it doesn't matter what user name you type in. This name will appear in the list of all players when you type /list in SPC.

Tip: Check that offline-mode is set to true in the server config file. \.minecraft\server\properties

Black screen or lag when starting single player

If Minecraft was working perfectly fine before you tried to use any of the new snapshots from Minecraft 1.3 then computer power might be your problem. Probably not memory but most likely CPU. If you see 100% values for CPU then you know the culprit straight away.

It seems that the new snapshots are resource hungry, especially on older computers that run XP. Now that single player and SMP have been merged, the local (background) server will always run even if you want to play offline single player. Sadly there's nothing you can do about the server running in the background, Jeb's hard coded it into the game.

If you want to find more clues as to why things are going pear shaped then take a look at the Minecraft server logs which are located under \.minecraft\server. You should see log files with incremental numbering. Just open one of these in notepad and scroll down to the last line. Sometimes you'll see the "[WARNING!] Did the system time change, or is the server overloaded?" This is a sure sign that your computer is struggling to cope with Minecraft.

Having experimented with an older XP laptop we found that increasing the Java RAM did nothing to improve the problem. However, downloading the latest version of Java did make some difference. Other tricks to improving performance include disabling wi-fi and antivirus completely while you play Minecraft (just remember to flick it back on afterwards). Close unused programs such as MS Word, Chrome, iTunes etc. Then open task manager and kill anything which you don't really need e.g. RealPlayer scheduler, Apple mobile crap, vmware tray, magic disk, winzip tray.

If you're feeling brave you could try changing your graphics driver settings. For us, we opened the ATI Radeon settings by right clicking the desktop > properties - display settings - advanced. If you see options for Direct3D or OpenGL change those to favour performance instead of quality. This should improve things drastically.

You get "Unfortunately we can't automagically download the server for this snapshot. Go download the server, and extract it to.." when you try to play single player?

Don't forget that Minecraft 1.3 is a merge of single player and SMP so there are now two jar files. One of the jar files is in a bin folder and the other in the server folder. You MUST copy both of these jar files to the correct places. So you'll end up with:

\.minecraft\bin\minecraft.jar
\.minecraft\server\minecraft_server.jar

You can download the jar files directly from our site. Just visit the relevant snapshot page: Minecraft

Lag and flickr

Starting in 12w18a and getting worse in 12w19a, flicker and lag seem to be common issues. Again, it all comes down to hardware. Our XP machine was really struggling whilst our dual core Win 7 machine was better. You'll need to adjust your graphics settings and close/kill un wanted processes to reduce lag as much as you can.

The majority of lag issues are caused by bugs and memory leaks. There is nothing you can do to stop these until Jeb finds a fix. For now, it's a case of patching the wounds to keep the game running.