vim-grammarous: Grammar check failed with exit status 1

[bondhugula]

Running :GrammarousCheck yields:

vim-grammarous: Grammar check failed with exit status 1:

java -version
openjdk version "11.0.28" 2025-07-15
OpenJDK Runtime Environment (build 11.0.28+6-post-Ubuntu-1ubuntu122.04.1)
OpenJDK 64-Bit Server VM (build 11.0.28+6-post-Ubuntu-1ubuntu122.04.1, mixed mode, sharing)

The plugin was installed via vundle. Commit ID at .vim/bundle/vim-grammarous/

commit db46357465ce587d5325e816235b5e92415f8c05 (grafted, HEAD -> master, origin/master, origin/HEAD)
Author: Linda_pp <rhysd@users.noreply.github.com>
Date:   Mon Nov 30 20:07:57 2020 +0900

    Merge pull request #87 from matze-dd/master
    
    Display all replacement suggestions from LanguageTool

The command it's running is below with the real error:

Error: LinkageError occurred while loading main class org.languagetool.commandline.Main
	java.lang.UnsupportedClassVersionError: org/languagetool/commandline/Main has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 55.0

It'll be extremely helpful if there is a debug log that actually logs this command and error accessible from vim via a ':.." command.

[bondhugula]

To support the newer class file, updating to JDK 17 yields:

java -jar /home/uday/.vim/bundle/vim-grammarous/misc/LanguageTool-6.6/languagetool-commandline.jar -d WHITESPACE_RULE,EN_QUOTES -c utf-8 -l en --api /tmp/vrfMiVc/1
Unknown parameter: --api
Usage: java -jar languagetool-commandline.jar [OPTION]... FILE

Looks like version this is unsupported as well.

[jmriff]

I receive the same error:
":messages" in vim produces the following:

Messages maintainer: The Vim Project
"test_grammar.txt" [noeol] 1L, 83B
vim-grammarous: Grammar check failed with exit status 1:

java --version
openjdk 21.0.9 2025-10-21
OpenJDK Runtime Environment (build 21.0.9+10-Ubuntu-124.04)
OpenJDK 64-Bit Server VM (build 21.0.9+10-Ubuntu-124.04, mixed mode, sharing)

Package Manager: Plug
.vimrc settings:

Plug 'rhysd/vim-grammarous'
let g:grammarous#languagetool_cmd = '/usr/bin/java -jar /home/tkuzoan/.vim/plugged/vim-grammarous/misc/LanguageTool-6.6/languagetool-commandline.jar'
let g:grammarous#languagetool_lang = 'en-US'

Thanks.

[bondhugula]

To support the newer class file, updating to JDK 17 yields:

java -jar /home/uday/.vim/bundle/vim-grammarous/misc/LanguageTool-6.6/languagetool-commandline.jar -d WHITESPACE_RULE,EN_QUOTES -c utf-8 -l en --api /tmp/vrfMiVc/1
Unknown parameter: --api
Usage: java -jar languagetool-commandline.jar [OPTION]... FILE

Looks like version this is unsupported as well.

This issue is due to incompatibility with newer LanguageTool versions 6.0 and higher. I can confirm that it works with LanguageTool 5.9, which is available here: https://languagetool.org/download/archive/. The --api option was removed long ago.