Error after running rake gems:install
===

I want to install the fedena school management system. When I type `rake gems:install` I get the following error:
 

    /usr/local/share/gems/gems/rake-0.8.7/lib/rake/alt_system.rb:32: Use RbConfig instead of obsolete and deprecated Config.
    (in /var/www/html/fedena)
    rake aborted!
    undefined method `name' for "Ascii85":String
    
    (See full trace by running task with --trace)


What shoud I do?