Hi MungoBBQ,
Have you installed the correct Bios for your region of games.
If not, when you start RetroX, and if using the standard user interface, should have 3 lines top left, with RetroX to its right.
Click on those 3 lines, click on settings, then on Device settings, and at the top will be the Bios manager.
Click on that option, and scroll down to Playstation Bios v1, search on Google "Download Playstation Bios scph1001.bin".
Download it, and place on your SDcard or into internal memory, in your download folder, that way it will be easier to find it later.
If its compressed, use an App called "ZArchiver" (Google Play Store - Is free to use), and will extract it for you.
Click on Playstation Bios v1, and tell it where the Bios is located in the download folder, or wherever you placed it.
Then close RetroX down, by pressing on Back button on your device.
Once you restart RetroX hopefully the Playstation Bios v1 will now be ticked, then retry the PS1 emulator again.
Hope that helps my friend.