Take the 2-minute tour ×
Arqade is a question and answer site for passionate videogamers on all platforms. It's 100% free, no registration required.

After pressing the log in button it would said updating minecraft and after that it said Failed to launch
Fatal error occurred (4): null
I have forced an update and updated Java but it still doesn't work. Not even the demo works.

share|improve this question
It's possible that something may be blocking the download. Take a look at your firewall settings and see if that's the problem. –  Coronus Mar 11 '13 at 22:08
Is this a fresh install, or one that worked previously? –  Coronus Mar 11 '13 at 22:09

2 Answers 2

It's likely your antivirus/firewall. Apparently Avira 2012 and McAfee have been known to prevent the connection to Minecraft update servers.

Here is one such report

If you're comfortable doing this, you could try temporarily disabling your antivirus while Minecraft updates.

share|improve this answer

I had this problem before, and I had to delete my minecraft.jar to get there.

For Windows: Win + R. Then inside the text box type %appdata%. Go to your .minecraft folder and find your bin folder, and inside of that delete minecraft.jar. Then open the Minecraft launcher and click "options", then click "Force Update". Then log in to Minecraft, and done.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.