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Wollok Environment

These are main instructions to get Wollok installed in your machine:

You need to install previously a Java Virtual Machine 1.8.

Download it!


  • Don't use Java Updates tools. Use above link.
  • JDK 1.8 recommended (there could be potential problems with Wollok Game running 1.9 or newer versions, check the specific troubleshooting page)
  • It has to be a JDK (Java Development Kit), since it has a compiler. A JRE (Java Runtime Environment) won't work.
  • If you are already using Eclipse and Java 1.8, you can ignore this step.

First time

As Wollok is an Eclipse-based platform, you install Wollok IDE by uncompressing Zip / Tar.Gz file (depending on your OS platform):

  Win 32  Linux 32  OS X


As soon as a new version is available, IDE will ask you to update your environment:

In this case double-click notification message to activate Update Process. You can also do this manually by activating Help > Check for Updates option. A Wizard is shown:

Go forward and press finish button. Before upgrade installation is complete a confirmation dialog will appear:

Click Ok, restart Wollok environment and then you will have last upgrade correctly installed.

Update Site Installation

This option is for advanced users who already have an Eclipse installation and want to add Wollok plugin. This step is not needed if you downloaded and installed Wollok compressed files successfully.

Update Site requires a JDT Eclipse Installation (since it is a Java-based platform). In order to add Software Update Site please follow this steps:

IDE shows splash screen but does not start

If splash screen is shown but IDE doesn’t start, maybe you are not pointing to the right JDK, so check this out in your environment and Wollok ini file.

Cannot create a Wollok project

If your installed IDE doesn’t allow you to create a Wollok project / Wollok class, maybe your Wollok environment is pointing to a non-Java 1.8 version, or just a JRE, so it can’t compile wollok sources. Once again, check JDK configuration in your environment and Wollok ini file.

IDE does not start with exit code 13

If trying to start Wollok IDE you get an error like this:

problem could be because
  • you are pointing to an unexistent JDK in wollok.ini (check -vm parameter). Correct it following this steps
  • you invoke "Java Updates" application. This is a known problem. In this case, solution should be a) uninstall current JDK, b) install new JDK as shown in this page, and c) start Wollok normally.

Missing dependencies to Wollok plugins while executing a file

It is certainly a non-descriptive message (we’ll work on it). Problem is you are trying to execute a test, program or Wollok file that is not located in a source folder of your Wollok project. By default a standard Wollok project has a "src" source folder. If you create a file outside this folder, it won’t be recognized as an executable one. To solve this you have to move the conflicting file(s) to src or any other source folder.

Mac: Failed to create the Java Virtual Machine

If this error message appears on your Mac, follow this instructions.

Mac: Wollok is damaged

First time you open Wollok executable program on your Mac, this window may show:

You can solve it opening a terminal and writing down:

xattr -d

After that executable file should be opened without any issue.

Mac: Executing unsigned application

Mac OS X implements a new security system only allowing the execution of application developed by registered developers. Also the applications should be distributed by Apple validated channels, as App Store. As Wollok development team is not registered an exception should be created in order to run Wollok.

More details of how to configure the exception to run Wollok is available in Apple support site.

Mac: Translocation App Problem

Version 10.12 of OS X introduces a new security system called Gatekeeper. This new system has as objective avoiding the undesired execution of programs. So that, the downloaded applications cannot be executed from the Download folder, or any other folder where the browser originally put it. To be able to execute the application, it should be moved to another folder. This operation should be performed using Finder. Once it has done, Wollok is able to execute normally.

Pointing to the right JDK in your environment

Sometimes, your Operating System is pointing to an old java installation. You have to check JAVA_HOME environment variable (and PATH variable too), in a command line tool:

$ env | grep JAVA // Linux & Mac
> SET JAVA_HOME // Windows
You can change to a JDK 1.8 installation, following this instructions.

Pointing to the right JDK in Wollok ini file

In Wollok installation root folder, you can open a text editor for wollok.ini file. Then you can point to a specific JDK 1.8 with -vm option:


Very important: don't add any space or ENTER character in .ini file, otherwise future Wollok updates won't work (there will be a parse error)

Eclipse JDK Configuration

Check this configuration: Windows > Preferences > java > Installed JREs. If you see no JDK at all, or a non-1.8 JDK, you can change it this way:

  • Add > Standard VM > next
  • Choose a JDK 1.8 installation directory. Eg: /Library/Java/JavaVirtualMachines/jdk1.8.0_91.jdk/Contents/Home

English language setting

If you would like to run Wollok IDE in the english version, it is necessary to add the following instruction as a new line at the end of wollok.ini, located in same path where you downloaded Wollok:


  What should I do if I find a bug?

Wollok is a continuous evolving software, so it is likely you find problems, or enhancements to propose. Please feel free to report it in our Issue Tracker.

Some tips before you open a new issue:

  • Most important thing is to put an intention-revealing title, explaining the problem and the steps to reproduce it. Without this is nearly impossible for us to solve errors.
  • Write your issue in your favorite language, whichever it is.
  • Before creating a new issue, take a time to see if it was already reported by someone else
  • Labels also help to filter issues:
    • Show stopper: this issue should get maximum priority since it prevents people from working
    • Bug: a system error (nevertheless you can work)
    • Usability: when application has a confusing behavior for users. As Wollok is a didactic tool, consistency is a very important attribute.
    • Enhancement: if you want to request a new feature
    • Nice to have: for wished (but not prioritary) requirements
    • Question: when you doubt whether certain situation could be a bug or not.