Thanks for the explanation from Jonny and for the documentation page. However, something has gone wrong. I replaced the default maps.xml file with the one I found in one of the postings in the thread. When I tried to start the program this morning, the splash screen displayed and remained on the screen. When I tapped the screen, the program closed. So, I removed the program and re-installed it from the CAB file. Same thing - splash screen and shutdown. What do I need to do to get the program running again? Thanks
After that (as a quick fix) you can just delete the whole folder and start OMM again.