Excelsior JET 12.0 Maintenance Pack 1

Excelsior JET 12.0 Maintenance Pack 1 (MP1) is an optional update that fixes multiple customer issues. It incorporates all hotfixes you may have received from Excelsior Technical Support prior to September 28, 2017.

Excelsior JET 12.0 MP1 is a prerequisite for Java SE 8 Update 144 support.

WARNING: Maintenance Packs fix particular problems reported by Excelsior JET users and discovered by Excelsior test engineers after the release of the respective version of the product. They are tested on a representative subset of the test suite used during preparation of the original release. We therefore only recommend you to install Maintenance Packs in the following cases:

  • You have been advised to do so by an Excelsior support engineer;
  • You need to switch to a Java SE (micro)version supported through a Maintenance Pack;
  • You want to try a new technology from Excelsior that requires installation of a particular Maintenance Pack; or
  • You are experiencing a severe problem, such as compiler or application crash or incorrect application behavior.

Release Notes

The most important issues resolved in Excelsior JET 12.0 MP1 are as follows:

  • JET-9418: Improve support for Windows 8 and Windows 10 (Windows)
  • JET-9583: Compiler crashes if the "Full Stack Trace" option is enabled (Windows/x86, Linux/x86)
  • JET-9602: Support Eclipse RCP option noExit and property osgi.noShutdown
  • JET-9609: Compiler crashes with "com.excelsior.jope.comm.CallError: invalid index at line 1581 of BaselineEnv.ob2 at parseLambdaClass" (Windows/x86)
  • JET-9621: Incorrect code generated for spring-context-***.jar (*/AMD64)
  • JET-9627: Complete hang if StackOverflowError gets thrown during memory allocation
  • JET-9654: High disk footprint reduction does not work when used from xpack (Windows/x86, Linux/x86)
  • JET-9687: Compiler crash "assert at src/u/xcMain.ob2:4013" on customized Tomcat
  • JET-9692: Tomcat 7.0.80 and 7.0.81 crash when compiled with Excelsior JET ("Attempt to compile synthetic class file" JET RUNTIME crash)
  • JET-9730: Graphical applications may hang at startup on macOS (macOS)
  • JET-9731: Remove unnecessary heap unlocking


If you are a registered customer of Excelsior JET 12.0, but have not received a user/password combination for MP1 download, request it from our Support Dept. at support@excelsior-usa.com.

Maintenance Pack 1 + Java SE 8 Update 144 Support (prebuilt profile)

Installation Instructions

MP1 installs on top of the original Excelsior JET 12.0, possibly with previous updates applied. If you need to make a fresh installation, install Excelsior JET 12.0 first, cancel JET Setup, and apply MP1.

To update an existing Excelsior JET installation, launch the downloaded executable and follow the on-line prompts. Upon successful copying of Maintenance Pack files, JET Setup will launch automatically and apply the Maintenance Pack.

Profile Management

Installation of MP1 does obsolete your existing profiles. (JET Setup backs them up, so if you rollback to the previous update level, they will be restored.) The pre-built profile bundled with this Maintenance Pack becomes the active profile automatically. If you do not want to use it for any reason, you can either create a new profile or refresh all or some of the obsolete profiles.

The procedure of profile refresh is as follows:


JET Setup is launched automatically upon a successful installation of MP1. Select the profile that you want refreshed and click Refresh.

OS X / Linux

  1. Run JET Setup to display the list of profiles:

    jetsetup -show-profiles
  2. Locate in the list the outdated profile(s) that you need to refresh and write down their numeric indexes.
  3. For each profile index in your list, run JET Setup as follows:

    jetsetup -refresh-profile profile

    where profile is the profile index.

Update Management


To roll back to the previous update level, select Manage JET Updates in Excelsior JET Start Menu and click Undo.

Rollback does not remove the installed updates and associated profiles, so you can reapply MP1 later without installing it. Select Manage JET Updates and click Redo until it displays the current configuration as "jet-1200-mp1".

OS X / Linux

  1. Run JET Setup to display the list of installed updates:

    jetsetup -show-updates
  2. Locate in the list the updates which you need to activate. Then run JET Setup again as follows:

    jetsetup -activate-update list

    where list is a colon-separated list of update names.

  3. Display the list of profiles available for the new combination of updates:

    jetsetup -show-profiles
  4. If necessary, create new profiles.

Stay Tuned

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