This error occurred with the Spoofax 2 beta version running on a Windows machine:

g.esv/2.0.0-beta1/org.metaborg.meta.lang.esv-2.0.0-beta1.spoofax-language!/
[INFO] Loading dialects
[INFO] Generating Spoofax sources
[INFO] Building file:///C:/Users/dsurchek/workspace_spfx/com.oracle.obiee.expressions
[INFO] Building 1 sources, 0 includes of language impl. org.metaborg:org.metaborg.meta.lang.ts:2.0.0-beta1
[INFO] Building 3 sources, 0 includes of language impl. org.metaborg:org.metaborg.meta.lang.template:2.0.0-beta1
[INFO] Building 7 sources, 0 includes of language impl. org.metaborg:org.metaborg.meta.lang.esv:2.0.0-beta1
[INFO]
[INFO] --- build-helper-maven-plugin:1.10:add-source (add-source) @ com.oracle.obiee.expressions ---
[INFO] Source directory: C:\Users\dsurchek\workspace_spfx\com.oracle.obiee.expressions\src\main\ds added.
[INFO] Source directory: C:\Users\dsurchek\workspace_spfx\com.oracle.obiee.expressions\src-gen\stratego-java added.
[INFO] Source directory: C:\Users\dsurchek\workspace_spfx\com.oracle.obiee.expressions\src-gen\ds-java added.
[INFO]
[INFO] --- spoofax-maven-plugin:2.0.0-beta1:pre-compile (default-pre-compile) @ com.oracle.obiee.expressions ---
Jul 07, 2016 3:23:12 PM java.util.prefs.WindowsPreferences <init>
WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0x80000002. Windows RegCreateKeyEx(...) returned error code 5.
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 15.477 s
[INFO] Finished at: 2016-07-07T15:23:12-04:00
[INFO] Final Memory: 104M/343M
[INFO] ------------------------------------------------------------------------

Submitted by Guido Wachsmuth on 9 August 2016 at 15:56

This is related to https://yellowgrass.org/issue/SpoofaxWithCore/122. Sebastian was working on replacing the preference store API in pluto with a lightweight embedded database, which would also solve this issue.

This should be solved in the latest build, since the registry is not used any more by Pluto.