Eclipse Bug: Unhandled event loop exception No more handles

Question

I\'ve built a GUI using Swing and the MigLayout.

I am using Eclipse 4.2.2 (64-bit) on Windows 7 Ultimate. Every time I click back into the window to edit my code, a

Answer 1

Wow, what a variety of causes of these error messages! I'll throw one more out:

In my case, Eclipse 4.17 on Ubuntu 16.04LTS was showing these messages for multiple operations. It turns out that 16.04LTS has GTK 3.18, but Eclipse 4.17 requires GTK 3.20. Updating GTK (https://askubuntu.com/questions/933010/how-to-upgrade-gtk-3-18-to-3-20-on-ubuntu-16-04) made the error messages go away.