Intermittent error using Zip.au3

[shornw]

Quite odd really, occasionally, and with no real pattern, I get the error:

'AutoIt3\Include\Zip.au3 (333) : ==> Object referenced outside a "With" statement.:'

As this is just testing at the moment, the files in the target location don't change, but every now and then I get the error, most times it works just fine

$f1 = FileFindFirstFile("C:\Temp\Test\*.au3")
While 1
      $file = FileFindNextFile($f1)
      If @error Then ExitLoop
      _Zip_AddFile($zip, $path & $file)
;    MsgBox(0, "", @error)
WEnd

Am I doing something wrong?

Thanks