Had the same issue as Sinled and iamntz, and had to disable the plugin.
I did a bit of investigation and found that both
source_rel were mixing forward/backslashes in the path. This is of course on a Windows machine.
Up to the Packages directory, backslashes were used (correct for Windows). Then after the
.., forward slashes were used (breaks Windows):
packages_path: C:\Users\<user>\AppData\Roaming\Sublime Text 2\Packages
source_abs: C:\Users\<user>\AppData\Roaming\Sublime Text 2\Packages\..\Packages/User/Atlantic.tmTheme
error: Error loading colour scheme Packages\Origami\User\Atlantic.tmTheme: Error parsing plist xml: Failed to open file In file "Packages\Origami\User\Atlantic.tmTheme"