I was in the same situation earlier this week. The way I got it to work was by following the instructions here to flash the tracker firmware, namely:
Getting the Tracker Edge Firmware
The Tracker Edge firmware can be downloaded from Github:
You will probably want to use the command line as there are additional commands you need to run after cloning the source:
git clone https://github.com/particle-iot/tracker-edge
git submodule update --init --recursive
Open Particle Workbench.
From the command palette, Particle: Import Project.
Run Particle: Configure Workspace for Device, select version 1.5.4-rc.1, 2.0.0-rc.3, or later, Tracker, and your device.
Run Particle: Flash application (local).
reset button: you need to open the tracker (oh, I did not know the particle usb reset command mentioned in the post above).