Before loading the placefiles, you must first download the required files for PSTC to work. This can be done by clicking the Configuration button on the main menu, and then going to the Required Files tab.
Figure 1: PSTC Settings Editor - Reqired Files tab
Next, go to the PSTC main menu and press the Placefiles to Add button on the menu bar. The placefile file path will then be copied to your clipboard.
Figure 2: PSTC Main Menu - Placefiles to Add menu item
Finally, in GRX open the Placefile Manager (Windows>Show Placefile Manager) and press the + to add the file. Paste the file path into the textbox using Ctrl+V or Right Click and Paste. Once you have the file path pasted, press ok.
Figure 3: GRX Placefile Manager - Adding a placefile