The Problem
Running the yEd install script results in the following output:
Unpacking JRE ...
Preparing JRE ...
Starting Installer ...
Could not display the GUI. This application needs access to an X Server.
Usually, this problem happens for Java versions other than the official Sun/Oracle Java such as OpenJDK. Moreover, on 64 bit systems, the installer (which uses 32 bit Java internally) can fail due to missing 32 bit X11 binaries.
The Resolution
First, it is necessary to determine which Java version is installed. This can be done by typing
java -version
in a terminal. The output should be similar to
java version "1.6.0_21"
Java(TM) SE Runtime Environment (build 1.6.0_21-b06)
Java HotSpot(TM) Server VM (build 17.0-b16, mixed mode)
for 32 bit Java installations or
java version "1.6.0_21"
Java(TM) SE Runtime Environment (build 1.6.0_21-b06)
Java HotSpot(TM) 64-Bit Server VM (build 17.0-b16, mixed mode)
for 64 bit Java installations. The important parts are the version number in the first line (it is recommend to use 1.6.0_17 or newer) and the last line that has to start with "Java HotSpot".
If the last line does not start with "Java HotSpot", the installed Java version should be replaced with the official Sun/Oracle Java, which can be downloaded from http://www.oracle.com/technetwork/java/javase/downloads/index.html. It suffices to download and install Java Platform, Standard Edition JRE.
If the install script aborts with the above output although official Sun/Oracle Java is installed, yEd has to be "installed" manually. This can be done by downloading the generic Java yEd Zip file from http://www.yworks.com/yed. Unzipping results in a new directory with two files, license.html and yed.jar.
Typing
java -jar /path/to/yed.jar
in a terminal (with /path/to/ replaced with the actual path) will start yEd.
With a simple shell script like
#!/bin/sh
java -jar /path/to/yed.jar "$@"
in a directory referenced in the $PATH environment variable, yEd can be started conveniently by typing the script's name.
And for those of you who unzipped the generic Java yEd Zip file and need/want a nice icon for their custom shortcut to yEd, here it is:
Related Questions
The yEd Linux installer aborts complaining about the "bitness" of the JVM. What can I do?