On my Arch Linux, Eclipse with Google Window Builder/SWT application, I am getting
Exception in thread \"main\" org.eclipse.swt.SWTError: No more handles [U
In my case I just had to install libwebkitgtk-1.0-0:
sudo apt-get install libwebkitgtk-1.0-0
Info on my machine:
$ lsb_release -a Distributor ID: Ubuntu Description: Ubuntu 16.10 Release: 16.10 Codename: yakkety
See also: https://rusya7.blogspot.com.es/2013/07/eclipse-internal-browser-is-not.html