issue with WriteXLS: The Perl script '' failed to run successfully

I have code which used to work OK but now always failed.
issue is WriteXLS. Example below.

WriteXLS(starwars,ExcelFileName="tableau.filename"starwars.xlsx,Encoding = "UTF-8")

Error is

No such file or directory\mikec\AppData\Local\Temp\RtmpiOHBFb/WriteXLS/1.csv
The Perl script '' failed to run successfully.

I have looked at output of tempdir(). No issue I can see. It is as if WriteXLS is truncating the first directory elements

[1] "C:\\Users\\mikec\\AppData\\Local\\Temp\\RtmpiOHBFb"

What I have found is an error on opening the library:

In system(cmd, intern = intern, wait = wait | intern, show.output.on.console = wait,  :
  running command 'C:\WINDOWS\system32\cmd.exe /c ftype perl' had status 2

There are many R packages that can write xlsx files, you chose one based on Perl; therefore you would need to follow the instructions here

my advice is, don't use this library unless it's doing somethings its competitors can't do for you.

Yes. It is from some of my earliest code.
Since then I have standardised on write_xlsx

But I figured I should work it out anyway
The workaround with the "perl =" below works - so I will leave it there:

WriteXLS(starwars,ExcelFileName="starwars.xlsx",Encoding = "UTF-8", perl = "C:/Perl64/bin/perl")