I guess as the plugin is no longer being supported, there is a corection you need to make to the code of the plugin which hasn’t been updated in line with the most recent wordpress updates. Follow these instructions to fix it.
1. Log in to the admin area of the site.
2. Go the the list of installed plugins by clicking the “Installed” link in the Plugins menu.
3. Deactivate the Inline Gallery plugin. It is not recommended to make changes to an active plugin.
4. Edit the Inline Gallery plugin by clicking the “Edit” link next to the Activate/Deactivate link. This will allow access to the actual PHP code of the plugin.
5. Find the text “admin_head” using the browser find functionality, just like you would search for text in a web page (usually “Control-F” on Windows, “Command-F” on Mac).
6. Change “admin_head” to “admin_menu”. There are two places you will need to do this.
7. Hit the “Update File” button.
8. Go back to the list of installed plugins and reactivate the Inline Gallery plugin.
Hope that helps!
