The following is the repository for redmine.
https://github.com/redmine/redmine
And the following is the repository for redmine-my-widgets-plugin
if we look at the file structure app/views/my
https://github.com/redmine/redmine/tree/master/app/views/my
there is a folder blocks which contains the partial which are widgets and displayed when added from select list.
similarly for redmine-my-widgets-plugin there is similar file directory structure
https://github.com/bradbeattie/redmine-my-widgets-plugin/tree/master/app/views/my
when i install this plugin the partials mentioned in this /my/block gets added in the my page -> select list so as to be added
When we add one of the plugins select list value then it displays 404 error
By looking at the structure the plugin, it looks like the plugin is overrided. Also there are no others config files, or lib files present in the plugin(except en.yml)
So, what can be done that the plugin will be able to atleast find those partials.
Basically, redmine is able to find the partial files as the names are displayed in the my page -> select list but when added it throws 404 error