Honestly, no idea.
You might have more success by loading it through a terminal. Most applications are quite vocal about their crashes and failures but nautilus
is comparatively silent. Perhaps running it like this killall nautilus && nautilus trash:///
might show you the problem.
You can forcibly delete everything in trash with this (but remember it will delete everything in there):
rm -rf ~/.local/share/Trash/*
If you want to rescue something from the trash, I suggest you browse it and pluck out what you need. You can do this from the terminal and you should also be able to do it via nautilus.
If you find the precise problem, or it persists, make sure you file a bug (ubuntu-bug nautilus
)