When starting standalone.bat on Windows, a file named "null" is created in the bin directory.
Looking at the standalone.bat file, I find this new line which was added:
rem Remove the gc.log file from the -version check
del /F /Q "%JBOSS_LOG_DIR%\gc.log" > null 2>&1
But, this is a typo. What it's trying to do is suppress the output of the del command. In unix, you'd redirect it to /dev/null. In Windows, you're supposed to redirect it to nul (with one L), as in this example line from slightly earlier in the standalone.bat file:
move /y "%JBOSS_LOG_DIR%\gc.log" "%JBOSS_LOG_DIR%\backupgc.log" > nul 2>&1