Checklist in Case of Problems

  • Make sure Java 8 or later is installed on your system. If you use the 32-bit version of LibreOffice/, you will also need to use the 32-bit version of Java (same for the 64-bit version). Java versions which are not from Oracle may not work, however contemporary version of OpenJDK will also work. If you're using an old version of Java or Ubuntu hasn't installed libreoffice-java-common you'll see a confusing error message like this.
  • LanguageTool 4.5.1 seems to be incompatible with Debian's outdated, stable version LibreOffice (source)
  • If you get an error that says Invalid memory access, make sure LanguageTool is installed in a path that has no special characters (use a-z, A-Z and 0-9 only).
  • If installation of LanguageTool in LibreOffice/OpenOffice didn't throw an error but you are not sure if it actually works, please load this document and follow the instructions in it.
  • If you see different results locally and on, that's for two reasons:
    • We usually run the latest version on which might have more rules than the latest release version.
    • For English, German, French, Spanish: We have some additional rules on that require large data sets not part of the download version (technical details).
  • For Mac users: LanguageTool requires Java 8 or later, which is available for the Mac only as a 64 bit version. You need the 64-bit version of LibreOffice 4.2 or later in order to use LanguageTool on a Mac and you also need to have 'Java for OS X' installed, additionally to Java 8 (Source: #74877).
    Older versions of LibreOffice and OpenOffice are only available in 32 bit, leading to an incompatibility so that LanguageTool cannot be used with these versions as a LibreOffice/OpenOffice add-on on the Mac. The only known workaround for these older versions is to use LanguageTool 2.2, which is still available from the download archive, for which a 32 bit version of Java 6 still exists. LanguageTool 2.2 also works with Java 6.
  • LibreOffice comes with its own integrated grammar checker (LightProof) which disables LanguageTool for English and Russian. Use Options -> Language Settings -> Writing aids -> Edit... to disable LightProof and enable LanguageTool for the language you are working with to make LanguageTool work.
  • Make sure Java 8 or later from Oracle is selected in LibreOffice (Tools -> Options -> Advanced) or (Tools -> Options -> Java). For Mac users: LibreOffice (Preferences -> LibreOffice -> Advanced).
  • If LanguageTool doesn't start and you see no error message, please check if the extension is enabled in the Extension manager (under Tools -> Extension Manager).

Common Problems with LibreOffice/ Integration

  • Note that if you have a 32-bit version of LibreOffice/OpenOffice, you will also need a 32-bit version of Java - LanguageTool will not work otherwise. Apache OpenOffice doesn't provide official 64-bit versions for Windows and Mac yet, so you will need a 32-bit Java on Windows and Mac.
  • If you get "Could not create Java implementation loader", please work through these suggestions. Note: if you have this problem on 64-bit Windows, it may be caused by a 64-bit version of Java. Apache OpenOffice on Windows is only built as a 32-bit application and will not work with a 64-bit Java. You need to use a 32-bit build of Java for Windows. (OOo bug #118346)
  • On Ubuntu, install the libreoffice-java-common package by calling this command in a terminal:
    sudo apt-get install libreoffice-java-common
    One problem solved by this is getting a long error message with "NoClassDefFoundError" during installation (see screenshot).
  • On Ubuntu, if you get a message similar to Exception in thread "Thread-402" java.awt.HeadlessException in LibreOffice/OpenOffice, see this stackoverflow answer. Note that the message might not appear in a dialog but only on the command line, so you might want to start LibreOffice/OpenOffice from a terminal window.
  • If you get "This media-type is not supported: application/" during installation, please consider resetting your OpenOffice user profile.
  • If you get Failed to load rules for language ... Caused by java.lang.ClassNotFoundException: Loading rules failed: Duplicate class definition: For some reason LanguageTool is installed twice as an extension in You can try deleting the directories listed in the error message after making a backup. (The directories to be deleted have random names like "EE31.tmp_" or similar - exit before deleting anything).
  • The menu items in LibreOffice/ get mixed up when both After the Deadline and LanguageTool are installed. The macro mentioned here might help you. This issue is tracked as ticket #215 at After the Deadline.
  • If you start LibreOffice/OpenOffice from the command line and you get a NoClassDefFoundError, make sure you're not starting LibreOffice/OpenOffice from the LanguageTool installation directory.
  • We have received reports from people that a re-installation of LanguageTool in LibreOffice/OpenOffice might be needed to make it work after the other issues have been resolved.

Known Limitations

Still need Help?

If LanguageTool still doesn't work properly for you, please post to the forum describing the problem and letting us know which version of LanguageTool, LibreOffice/ and which operating system you are using.