Media files don't show up in file manager but their folders can be seen I was tinkering with my Android's internal storage connected to my PC when suddenly all the media files (music and pictures) got deleted. The folders they belonged to remained unchanged. What happened, and is there a way to retrieve them?

Thank you.
You probably have 6.0 android.
You need to go settings>apps than tap on three dot button and select "show system" than find "External storage" and "Media storage" and clear cache and data for them. After that reboot phone and wait 5 minutes after booting to phone index files than connect to PC and see if you can find files now.