I am working on a Windows Installshield MSI installer that has Strawberry Perl as a prerequisite. This has existed for several years; I'm trying to modify it to install the latest version of Perl. In the Prerequisite Editor, the command I have specified runs a .bat file that uninstalls previous versions of Perl and runs the latest installer using msiexec.exe. The installation completes successfully, but Installshield reports that the batch command file returned an error. How can I find out what is going on, or at least suppress the Installshield message? This is Installshield 2019, by the way. Here is the batch file:

@echo on
MsiExec.exe /passive /X{0BE917CD-6CE8-1014-9C0C-9680A6A774DD} 
MsiExec.exe /passive /X{8075BCC9-804A-1014-97A8-A0999374D9D1}
MsiExec.exe /norestart /i strawberry-perl-5.42.0.1-64bit.msi  /qb /Le "c:\perl_install.log" 
echo Exit Code is %errorlevel% >> c:\perl_install.log

I don't get the output from the echo command in the log file, ether. Strangely, I get a string of Kanji.