Executando erro .bsh (ZereneStacker)

Estou tentando executar o programa ZereneStacker no Linux (estou usando um Chromebook Samsung 3). Baixei o .zip do programa daqui e extraí. De acordo com essa página de download, o arquivo .zip inclui:

ZereneStacker          executable launcher

ZereneStacker.bsh      launch script (provided for backward compatibility)

Após a extração, eu cdna pasta extraída ZereneStackertentei os comandos

sudo chmod +x ZereneStacker
sudo ./ZereneStacker

e

sudo chmod +x ZereneStacker.bsh
sudo ./ZereneStacker.bsh

Para ambos, a saída foi longa e incluiu o seguinte:

Fatal error: /home/user/ZereneStacker/jre/bin/java exists but is not an executable file

Preciso alterar mais as permissões? Estou faltando etapas de instalação ou ele deve ser instalado na primeira execução?

Aqui está a saída completa, caso seja útil:

sizeof(ptr) = 8
Physical memory = 2986188800
isSafeMode = 0
argv[0] = [/home/user/ZereneStacker/ZereneStacker]
launcherFile = [/home/user/ZereneStacker/ZereneStacker]
sigh... appdir = /home/user/ZereneStacker
arg0 = /home/user/ZereneStacker/ZereneStacker
argc = 1
endDir = /ZereneStacker
length = 33
argsLength = 0
appdir = /home/user/ZereneStacker
appdataName = /root/.ZereneStacker
appdataName = /root/.ZereneStacker
appdataZSName = /root/.ZereneStacker
configFileName = /root/.ZereneStacker/zerenstk.cfg
configFile = 0
mxStringFromConfig = 

mxString = -Xmx1024m
launchCmdFileName = /root/.ZereneStacker/zerenstk.launchcmd
launchOKFileName = /root/.ZereneStacker/zerenstk.launchOK
trying launchParamsFileName = /home/user/ZereneStacker/zerenstk.ini
initialization line = "{appdir}/jre/bin/java" {memsize} -DjavaBits={javaBits} -Dlaunchcmddir="{launchcmddir}" -classpath "{appdir}/ZereneStacker.jar:{appdir}/JREextensions/*" com.zerenesystems.stacker.gui.MainFrame

invocation line before possible tweaking = "/home/user/ZereneStacker/jre/bin/java" -Xmx1024m -DjavaBits=64bitJava -Dlaunchcmddir="/root/.ZereneStacker" -classpath "/home/user/ZereneStacker/ZereneStacker.jar:/home/user/ZereneStacker/JREextensions/*" com.zerenesystems.stacker.gui.MainFrame
argument 0 before tweaking: [/home/user/ZereneStacker/jre/bin/java]
argument 1 before tweaking: [-Xmx1024m]
argument 2 before tweaking: [-DjavaBits=64bitJava]
argument 3 before tweaking: [-Dlaunchcmddir=/root/.ZereneStacker]
argument 4 before tweaking: [-classpath]
argument 5 before tweaking: [/home/user/ZereneStacker/ZereneStacker.jar:/home/user/ZereneStacker/JREextensions/*]
argument 6 before tweaking: [com.zerenesystems.stacker.gui.MainFrame]
argument 7 before tweaking: [(null)]
Invocation line: ["/home/user/ZereneStacker/jre/bin/java" -Xmx1024m -DjavaBits=64bitJava -Dlaunchcmddir="/root/.ZereneStacker" -classpath "/home/user/ZereneStacker/ZereneStacker.jar:/home/user/ZereneStacker/JREextensions/*" com.zerenesystems.stacker.gui.MainFrame ]
statbuf.st_mode = 100644
Fatal error: /home/user/ZereneStacker/jre/bin/java exists but is not an executable file