Problem: RepreZen does not start on Linux with the following error in the error log (located in the active workspace in .metadata/.log): 


org.eclipse.swt.SWTError: No more handles [Browser style SWT.MOZILLA and Java system property org.eclipse.swt.browser.DefaultType=mozilla are not supported with GTK 3 as XULRunner is not ported for GTK 3 yet]


As the exception message states, the problem is that XULRunner is not ported for GTK 3 yet. So we need to use GTK 2 instead. The easiest way of achieving this it to add the following 2 lines to RepreZen.ini, which is located next to the RepreZen executable:


--launcher.GTK_version
2


Please note this has to be added before vmargs. The complete file will then look something like this:


-startup
plugins/org.eclipse.equinox.launcher_1.3.100.v20150511-1540.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.gtk.linux.x86_64_1.1.300.v20150602-1417
-pluginCustomization
plugin_customization.ini
# === HERE ===
# XULRunner is not ported to GTK3 yet, so you have to make it run in GTK2 mode:
--launcher.GTK_version
2
# ============
-vmargs
-Djavax.xml.accessExternalDTD=all
-Djava.net.preferIPv4Stack=true
-Xms256m
-Xmx512m
-XX:PermSize=192M
-XX:MaxPermSize=256M
-Djavax.xml.accessExternalDTD=all


See http://stackoverflow.com/questions/37099810/java-xulrunner-error-in-eclipse-swt-in-ubuntu for further details


Ubuntu 16

If RepreZen API Studio still fails to start, and you are on Ubuntu 16, check the workspace error log again and look for the following error:


org.eclipse.swt.SWTError: No more handles [Unknown Mozilla path (MOZILLA_FIVE_HOME not set)]


If you see this error then installing the following version of the libwebkitgtk package should fix things:


sudo apt install libwebkitgtk-1.0-0


RepreZen API Studio should now start.