Have you just upgraded to Yosemite and now when attempting to launch PhpStorm you get this message?

To open “PhpStorm” you need to install the legacy Java SE 6 runtime.
You just need to download Apple JDK 1.6.
- Apple JDK 1.6 download: http://support.apple.com/kb/DL1572.
JetBrains is not recommending you change the .plist file.
Also it’s worth noting that you need 1.6 as:
Current JDK 1.7 and 1.8 versions have several critical issues. We can’t default to the new JDK version until these issues are resolved.