If you want to take advantage of Debrief's support for background datasets, don't forget to read the instructions on how to configure their locations (shown below). Note, due to their size, the datasets probably aren't present in your Debrief installation, so you will have to request and then load them separately. In 2015 Debrief added support for the Natural Earth dataset, superceding the VPF and ETOPO datasets - so you probably won't need to configure them.
Natural Earth instructions are in Section 7.1.2, “Using Natural Earth”
VPF instructions are in Section 7.2.5, “Configuring Debrief to read VPF data”
ETOPO instructions are in Section 7.5.1, “Configuring Debrief to read ETOPO data”