Great. Thanks for the additional information.
Then, it seems like it is something that is happening when it tries to launch the "display" window (either Fullscreen, in the Action Window, or in Playing Now, depending on how you have it set up), that's crashing or making it hang. I'm really thinking it is a Visualization (or similar) thing. I've
seen this before when I had a broken installation of SoundSpectrum plugins.
Do you have anything like that installed? Did you previously (with MC17 or whatever)?
If so, uninstall them. Uninstalling and reinstalling might be all it takes.
Otherwise... Do you have any video files (simple AVIs or WMVs or whatever) that you can try? I'd like to see if video works, but something specific to Audio playback (like a visualizer or Track Info plugin, one of those things) is broken, or if all playback is broken.
And, lastly, this is a bit voodoo (but it could possibly fix a stuck plugin like that), but you can try:
1. Make a Library backup. Go to File > Library > Backup Library. Save the ZIP file somewhere you can find it in case you need it.
2. Uninstall MC19 completely. When it asks, preserve
both the Registry entries and the Library.
3. Reboot. Don't skip this step because you are lazy.
4. In Windows Explorer, go to:
C:\Program Files (x86)\J River\ (for 64-bit Windows)
C:\Program Files\J River\ (for 32-bit Windows)
And move or delete the
Media Center 19 folder if it is still there. If you haven't done anything fancy like customize skins and whatnot, you can just delete it.
5. Now, reinstall MC using the installer for the latest build.
6. It will come back up with your settings and library fully intact. See if that fixes it.
If so, hooray!
If not, then we're going to try again, but slightly different.
1. Uninstall Media Center again. But this time, check the box that says "Remove all Media Center registry entries."
2. Reboot. Again, don't skip it.
3. You shouldn't have to clear out the folder this time, so skip that part.
4. Reinstall using the latest build. This time, it will have reset all of your settings back to the defaults, but preserved your Library. Don't worry, we can restore your settings using the backup if this doesn't work, which is why I had you make that at the beginning.
5. Try it again.
Come back here either way and let me know what happened.