unpacking a platform package fails for windows if the archive file contains a symlink.

This is because Platform.java defines the (Unix) command ln -s for this purpose and windows/Platform.java does not overload this with an equivalent definition for windows.

An example of the full error message can be found in issue report #25 on Sduino project where I use symlinks in a platform package.

Symlinks are supported since Windows Vista by the command mklink. I suggest a modification for src/processing/app/windows/Platform.java like this (untested, since I don't have all this java stuff set up here):

--- src/processing/app/windows/Platform.java	2017年10月30日 11:04:26.000000000 +0100
+++ src/processing/app/windows/Platform.java.new	2017年11月06日 12:16:13.167549867 +0100
@@ -212,7 +212,10 @@
 return scripts;
 }
 
+ @Override
 public void symlink(File something, File somewhere) throws IOException, InterruptedException {
+ Process process = Runtime.getRuntime().exec(new String[]{"mklink", somewhere.getAbsolutePath(), something}, null, somewhere.getParentFile());
+ process.waitFor();
 }
 
 @Override

A similar modification might be useful for hardlinks as well.