iTunes will not play videos with 4k monitor

Hey Snackynak.

There may be a few reasons for this behavior. Are you streaming these videos or are you playing them from your computer? This could be an important factor. Also, was your previous monitor 4K as well or was it a lower resolution? Higher resolution content is much larger when streamed so that could be a factor as well. The "If the video quality is bad or it stops playing" section of If you can't watch or stream movies and TV shows in the Apple TV app lists a few steps or bits of information that may be helpful:

1. "If multiple people on your network are using the internet, your connection speed might slow down. Ask them to temporarily pause their internet activities.
2. If you're using a smart TV or streaming device, turn it off and back on again. If you're using an Apple device, restart it.
3. Tap or click the download button to try downloading the movie or TV show instead."

If those steps don't help, Get Support directly from Apple here.

Take care.

Greetings Snackynak,

To clarify here, is this issue only with purchased content?

If so then we can try the following steps on the PC:

1. Quit iTunes.

2. Press the Windows key on your keyboard. If your keyboard doesn't have a Windows key, press the Control (Ctrl) and Escape (Esc) keys on your keyboard.

3. Click on the magnifying icon or search field. In the search box, type %ProgramData%, then press the Return key.

4. Show any hidden files:

Windows 10: Click View, then select "Hidden items."

Windows 8: Click View, then click Options. On the View tab, select "Show hidden files, folders, and drives."

Windows 7: Click Organize, then "Folder and search options." On the View tab, select "Show hidden files, folders, and drives."

Open the Apple Computer folder, then the iTunes folder.

5. Delete the adi and SC Info folders: Right-click each folder and choose Delete from the menu.

6. Restart your computer.

7. Open iTunes and test.

Hope that helps!