Problems at installation or first run

The IDE does not start, it fails with some JAVA (JRE) missing message, like "Java Runtime Environment (JRE) or Java Development Kit (JDK) must be available..."

Since version 3.3.0 (Sept 2023) the Windows IDE includes a Java JRE (you can check this by looking for the JRE directory inside the installation directory, eg c:\geb3\ide\jre\ ), so normally you should not need to have Java installed in your machine for the IDE to work.

If are using a version that does not include the JRE, your machine has to have Java 17 (64-bits) installed (JRE or JDK); you can install it from here:

If you have a Java 17 JRE installed on your machine but it's not in your path, or the IDE cannot find in on startup, you can specify it by editing the file ide\geb.ini, inserting the lines (replace with your JRE path)

The format is the same as in the eclipse.ini for Eclipse IDE. See here.

IDE cannot connect to Internet

Since version 3.2.0 (April 2017) an Internet connection is only required for the Professional licence. If you have trouble validating your Professional licence online:

1. Make sure you have a valid license.

2. To check for Internet connectivity, and that the GEB license server is up, navigate your web browser to
It should display some "Status OK" message.

3. In some rare cases, it might happen that your network requires some proxy that is set inside your web browser, but it's not recognized by Java. To fix this, try editing your lib\ file inside the JRE 

I cannot compile/run when targeting a particular device

When using the IDE without a Professional licence, you are restricted to the shipped devices, which are signed. If you try to use an alternative device, or modify the signed devices, the IDE will throw an error. Depending on the case, you are allowed to modify some files inside the device (e.g. the configuration in setenv.bat and perhaps the mapping of I/O variables in deviceio.c. In case or doubt, contact support.

A Professional licence gives access to the GEB runtime source code to port your own devices or modify the included ones without restrictions.

Other problems

Please send us an email to

If you attach the following files, inside the IDE installation directory, we might be able to help you better: