After clicking “Install” on the plugin page for AdminImages on a DEV version of Omeka (2.5.1), the screen immediately went blank. I can’t now access any pages of the site at all via the browser; all are returning a 500 error.
Thanks John. Renaming the offending folder did the trick. Still need to figure out why that plugin doesn’t work in DEV, when all is fine in PROD. But low priority.