If you are using Ruby on Rails with Apache (or Apache ITK) and mod_passenger and you get an error while you are trying to upload a file through Rails application, you are probably facing the problem of wrong permissions set in the webserver_private directory of passenger. Passenger is not currently supporting ITK and is not [...]

If you run rake db:migrate and experience that error: then try to do this to solve the problem: download an older libmysql library dll, e.g. from here put it in your rails installation directory, e.g. C:/Ruby192/bin/ restart the rails server