Upgrading your Play app to a newer version



Let’s assume you have an existing app using Play! 2.1.A and a 2.1.B version was released. You want to update your environment to use that new release. Note: This tutorial was tested to be working with 2.1.* versions; A and B are two arbitrary numbers.

Updating environment

Like when installing a new version of Play:

  1. Extract the Play 2.1.B install package (zip) to %PLAY_HOME%\play-2.1.b. Attention: you must have read and write permissions on that folder.
  2. Open a command line, go to the parent folder of %PLAY_HOME%, open play-2.1.b folder, type play and enter. That will start the Play! installer. Wait for the installation to finish.
  3. To finish up, you must tell your system to use the new Play version. To do so you must go edit your environment variable “%PLAY_HOME%” from some-path\play-2.1.a to some-path\play-2.1.b.
  4. To test if everything is ok, open a command line, then execute play version. Check if the version displayed is Play! 2.1.B.

Updating projects

Now that your environment is using the newer version of Play you must update your (Eclipse) project’s imported files.

  1. Go to your project’s main folder, open project and edit plugins.sbt.
  2. Look for addSbtPlugin("play" % "sbt-plugin" % "2.1.a") and simply change the version to "2.1.b"
  3. Open a command line on your project’s main folder and run play eclipse, just like in the old days. Play startsr to fetch the updated files, remove the old ones and update all those import references. Just sit back while it does all the work.


And it’s done! But mind that… since we replaced the build.bat file, the following error will probably reappear:

Error occurred during initialization of VM
Could not reserve enough space for object heap
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

You know what to do. And since we replaced play.bat file, you may also want to add that -DapplyEvolutions.default=true argument to the play command (play for unix and play.bat for windows).