while upgrading redmine i received error:
don’t know how to build
after running: rake db:migrate:upgrade_plugin_migrations RAILS_ENV=production
You probably copied all your old plugins over the new ones. This is incorrect. Install it again on another machine and copy the plugins folder over your current busted install.
if on windows try renaming
C:\Program Files\BitNami Redmine Stack4\ruby\lib\ruby\gems\1.8\gems\mongrel_service-0.4.0
C:\Program Files\BitNami Redmine Stack4\ruby\lib\ruby\gems\1.8\gems\mongrel_service-0.4.0-x86-mswin32-x86-mswin32