I had always an error on packing my customized UI with the JS PACKER script, after applying several enhancements to the code. The error was saying "missing ; before statement".
Today I've found the reason why and since there is no UI bugtracker available at the moment I thought I will just let the people know here and hopefully somebody will create a ticket. The reason why JS PACKER isn't working, is definately a missing ; I've found it in the "effects.core.js" file on line 231: 230 if (result = /rgba\(0, 0, 0, 0\)/.exec(color)) 231 return colors['transparent'] just add a ; at the end of the line 231 and the PACKER should create correct packed JS code. I hope this will help at least someone out there!