I have installed Beta 2 OS X El Capitan and when I go to use programs it says I need "Legacy Java SE Runtime". I don't know how to get that, could someone help me.
Java SE Runtime
There are a couple of ways to do this but, since a good solution has already been posted here, I'll refer you to the thread:
https://forums.developer.apple.com/message/6338#6338
Download the latest Java from Oracle and then...
The solution is to edit
/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Info.plist and change:<key>JVMCapabilities</key><array> <string>CommandLine</string></array>To:
<key>JVMCapabilities</key><array> <string>CommandLine</string> <string>JNI</string> <string>BundledApp</string></array>- Save the changes and start up Photoshop - no problems!
NOTE... depending on what JDK you have loaded, you will need to change the 'jdk1.8.0_45.jdk' to whatever you have loaded.
To figure that out, simply look at what is in /Library/Java/JavaVirtualMachines/
To get the latest version of Java (the version referenced in the above solution), copy+paste the following into the URL bar of a broswer:
java.com/en/download/
You'll be able to edit the file referenced by using TextEdit (just copy+paste - don't worry about the boxes around words like string - they only need to be normal text)