Did you do any updates with Software Installer or with sudo apt-get
update/sudo apt-get upgrade ? If so, there may be no space left in the USB
stick. That has been my own recent experience.
There are two ways of getting around this impasse:
1. Use Synaptic Package Manager to unselect all but your native language
(there's a recent discussion of this process on The List) so that Software
Installer doesn't "run amuck" (that's the search term for the reference
above).
or
2. Use GParted to subdivide the 16GB thumb drive into smaller pieces, such as
4GB for the Trisquel installation and all the rest as file storage. The files
you subsequently save into the larger partition will stay there after any
restarts.
