QGIS Plugin used to restore layer states (visibility and style) from a print composer where those layers have been locked.
Once installed in QGIS, you can click on the plugin icon. The window will show all the composers in the project tha have the "lock layers" set. Select the composer and the map from which you want to pick layer states.
If layer styles are also locked, you can chose to import them or not.
Once you click OK, the layers corresponding to the selected composer will be updated.