After capturing a region using the "capture region" option by right-clicking on the Greenshot tray-icon, the "capture last region" function doesn't work any more - it was working until I upgraded yesterday to version 1.2.9.b112.
If it matters, I installed Greenshot through Ninite's installer (I have a bunch of software that I regularly use to update my system and all of my home computers, and I use Ninite for it).
Attached are Greenshot's log files.
Update - I just noticed that using the keyboard accelerator - shift-prtscrn works - it brings up the save menu. So looks like only manually selecting the "capture last region" option from the tray-icon doesn't seem to work at the moment.