The BlogManagementWidget class introduces an error in the SS3 admin area when attempting to view a site member record under Security.
This is due to use of Permission provider. The Permission class instantiates a singleton of every class which implements PermissionProvider And because the BlogManagementWidget inherits Widget (which doesn't exist) the whole thing falls over.
I just found this same issue recently too... however once I do install the widget module I then have issues accessing the BlogTree and BlogHolder pages to edit content.
Dependency "silverstripe/widgets" needs to be added to composer.json, no?
I'm not so sure this is still a bug. There have been many changes to the blog module since this ticket was created. Also, if it is still a bug, I'd rather see the blog module not require the widgets module rather than just adding a requirement and calling it a day.
The existing blog widgets could be split out into its own dependency and marked as a suggested library, alongside silverstripe/widgets. See suggest# at http://getcomposer.org/doc/04-schema.md.
It could be argued that it fragments the module somewhat, but not everyone will use or want widgets on their blog.
Unfortunately there's no easy way to include the classes in the core module that "activate" when the widgets module is installed. Is there?
Fixed with ee53229
BLOGMANAGEMENT permission is now specified by the BlogHolder class, which doesn't depend on the Widgets module.