Text cannot be entered into dialog boxes on macOS 10.13 (High Sierra) when ImageJ is using Java 6. FileImportVideo) and plugins that use QuickTime for Java fail with 64-bit versions of Java and with OS X 10.10 (Yosemite) and later.
After upgrading to a newer version of Mac OS X (Yosemite 10.10 and El Capitan 10.11) or macOS (Sierra 10.12 and High Sierra 10.13), you may end up getting an annoying new pop-up message whenever you start your computer. It says, “To use the java command-line tool, you need to install a JDK.” It asks you to click “More Info” and visit the JDK (Java Developer Kit) download website.

- If your Mac with OS X Yosemite needs Java for application compatibility, online banking, or any of the many other reasons, you can manually install one of two versions of Java that are compatible with OS X 10.10, or the latest version of JRE 8, or an older version from Apple that remains compatible with the latest version of OS X.
- After upgrading to yosemite, java 6 jdk is no longer available, remember that jdk 6 for mac osx is a 32-bit application, older eclipse releases needs a 32-bit jvm in order to run properly, a 32-bit application cannot run with a 64-bit jvm like java 7 or 8, so you need to install jdk 6 to run those java applications that needs a 32 bit virtual machine.
The reason you’re receiving this message is due to the removal of Java support in newer versions of OS X for security reasons. Older software such as Adobe Photoshop and Illustrator requires legacy Java support. Without a compatible Java command-line tool for these software, you’ll get this pop-up every time you turn on your Mac computer.
Update Java Mac Os

When you visit the download website to update Java, you find that the issue isn’t resolved! You’re still getting the same pop-up. This isn’t a complicated issue to fix, but it is an indirect one. The problem is that you’re not being routed to the correct download website when you click “More Info.”
Apple could have remedied this issue by programming the “More Info” button to direct you to the right fix. Here are the steps you can take to finally rid yourself of this pop-up:
Java For Yosemite Mac Os X 10 10

Java
Fix Java Command-Line Tool Pop-Up on Mac OS X

Java For Yosemite Mac Os 10.13
- Download Java for OS X 2017-001 aka Apple’s version of Legacy Java Command-line tool.
- Mount the .dmg disk image file and install Java 6 runtime for OS X.
- Restart your Mac and enjoy the absence of this Java command-line tool error pop-up!
