- Oracle's Java version 7u25 and below have been disabled by Apple on OS X. Updating to the latest release will allow Java to be run on Mac OS X. » Download latest Java » After I updated to Sierra, Yosemite or El Capitan, why am I told to install Java after I already installed the latest Java?
- The El Capitan installer is downloaded to the /Applications folder, with the file name Install OS X El Capitan. If you have already installed El Capitan and wish to now create a bootable installer, you can force the Mac App Store to re-download the installer.
Java is no longer installed with a OS X 10.11 El Capitan clean install, and you’ll find that after updating a Mac a prior version of JRE may no longer function.
I have installed El Capitan on my Mac, and whenever the mac boots, this screen appears. Note that this window appears many times while using the mac. Also, I have installed the latest java version (8.51) installed from the java.com page. How do I fix this.
You may come across when trying to use some particular applications or web content, “This application requires the legacy Java SE 6 runtime which is unavailable for this version of OS X.” error message, which means if you want to run that app you’re going to need to use an older version of Java.
If you do not need Java, you should not install Java. Java is, and always has been, the source of many security holes.
Here’s how you can install JRE (Java Runtime Environment).
Step 1. Open Safari and go to the Oracle Java downloads page and download the JRE .tar.gz version. You should end up with a file named something similar to jre-8u65-macosx-x64.tar.gz.
Step 2. Go to your Downloads folder and extract the JRE download or use Terminal to extract files:
Step 3. Open Terminal
Step 4. Edit the Info.plist file within to enable the JRE to be used from the the command line, and from bundled applications:
Step 5. Move the JRE folder to the correct location:
Type password on prompt.
Be sure you are in the correct directory (the JRE folder) when you issue this command, because it will move your current directory to /Library/Java/JavaVirtualMachines/!
Step 6. Create a link to add backwards compatibility for some applications made for older Java versions:
You should be done now, so try and open the application. If it does not work, some applications require legacy Java 6 to be installed.
You can have it installed without actually using it, however, it’s possible to trick the applications into thinking legacy Java 6 is installed, without actually doing so.
Step 1.Disable SIP (System Integrity Protection) in OS X El Capitan. Here is tutorial to disable and enable SIP.
Step 2. Trick some applications into thinking that legacy Java 6 is installed by creating two folders with the following commands in Terminal:
Step 3. Don’t forget to enable SIP again after creating these directories.
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Error creating thumbnail: Unable to save thumbnail to destination
Download Java 8 For Mac El Capitan
Think different.
macOS (formerly called Mac OS X, then OS X) is Apple's desktop operating system. It is the second most common desktop computing platform after Windows. This page details issues specific to using ImageJ on macOS systems.- 2Troubleshooting
- 2.1ImageJ becomes very slow after running for a while
- 3Frequently Asked Questions
See also the Java 8 page for OS-X-specific issues.
See also the Troubleshooting page.
ImageJ becomes very slow after running for a while
There are several reasons ImageJ can run slowly on macOS.
Java painting bug
On OS X, older versions of Java 8 (prior to 1.8.0_45)—as well as all versions of Java 7 (including 1.7.0_80)—are extremely slow at displaying images. You should either upgrade to the latest version of Java 8, or revert to Java 6 (see 'Frequently Asked Questions' below).
Download Java 6 For Mac El Capitan
Window menu bar bug
There is a bug in Java 8 on MacOS which causes the application to drastically slow down as many windows are opened and closed over time. Make sure you are using the latest version of Java 8, as well as the latest version of ImageJ.
App Nap
On recent versions of OS X—10.9 'Mavericks' and later—there is an 'App Nap' feature which dramatically slows down applications that are not in the foreground. Leave ImageJ in the foreground while it is processing to avoid this issue. (There are also variousways to disable App Nap on your machine, but we have not had much success with them. If you find a solution that works, allowing ImageJ to run fast in the background, please tell us on the forum!)
No title bar in file chooser dialogs
On macOS 10.11 'El Capitan' and later, the operating system no longer includes a title bar for file chooser dialogs. See e.g. this JDK bug discussing the issue.
As a workaround, you can check 'Use JFileChooser to open/save' in the Edit › Options › Input/Output... dialog.
See also the Frequently Asked Questions page.
How do I run ImageJ with Java 6?
It is unfortunately no longer feasible to install Apple Java 6 on current versions of macOS. However, ImageJ should work OK with Java 8. If you have difficulties, please post on the Image.sc Forum.
At any time, you can verify which Javas are installed on your system using this script.
How do I run ImageJ on Yosemite?
Install the Java 8 JRE or Java SE 8.
How do I run ImageJ on El Capitan?
Unfortunately, El Capitan has some new java-related issues. If you upgraded to El Capitan and your Java 8 installation is not being detected properly:
- Try installing the Java SE JDK.
- If that does not work, see this guide for steps which could get things working again.
- Alternately, ImageJ still works on El Capitan with Java 6 (see above).