PinballY writes some internal technical information to a "log file" while running. This is a simple human-readable text file that you can review to see the additional technical detail. This is mostly intended for troubleshooting purposes, to provide more transparency on the inner workings of the program when something goes wrong. PinballY tries to keep the graphical part of the UI friendly and non-technical, but that has the tradeoff that it hides a lot of information about what's going on inside the program. The log file is meant to help uncover some of that hidden internal detail when necessary, without bothering you with it when it's not.
The dialog shows the location and name of the log file, in case you want to inspect its contents. Click on the filename link to open the file in Notepad.
Note that PinballY erases any old contents of the log file each time it start up, so that the file doesn't grow to enormous proportions over time. If you want to save the log output from a particular program session for later review, be sure to move or rename the file before you run PinballY again, so that the new session doesn't erase the old copy that you wanted to save. The program always writes the log using the same file name, so all you have to do to save a particular copy is rename it or move it to a different folder.
You can select the type of information included in the log file. The default settings exclude most items, to reduce the size of the file. Writing more information to the file slows down the program a little and obviously uses more disk space, plus it's harder to find the information you're looking for if you have to sift through tons of unrelated information. So the program lets you turn individual logging features on and off. When things are working well, you can turn everything off to minimize overhead and disk space, but if you're having a problem with a particular area, you can enable logging for that feature.
Player system setup: Information on setting up the configured pinball player systems, and for the process of searching for their table files and table databases. This gives you detailed information about how the system is interpreting the settings information for each system, such as all of the folder paths involved, and shows where it's looking for table files and table information databases. This can be helpful if PinballY isn't finding all of your tables or isn't finding bibliographic information that you've previously entered (titles, manufacturers, years, etc). It can also help figure out the problem if you can't launch (play) any of a system's tables successfully.
Real DMD: Information about detecting and setting up your real DMD device, if any.
Media file searches: Enables logging for media file searches, showing where PinballY is looking for media files to display when games are selected in the "wheel". This can help track down why images or videos aren't showing up in the UI when they should be.
Media capture: Logs information when capturing screen shots and videos for your games. This lets you see any error messages from FFMPEG. This can be helpful if the capture process is producing empty files or blank images.
Table launch: Logs details when trying to launch a table with a player system. This can be helpful if a particular game won't launch correctly. (If none of the tables for a particular system will launch correctly, you might also try enabling "player system setup" logging above to see how the system is being configured overall.)