You might be receiving an error message because the FooEvents plugin was partially uploaded or uploaded more than once to your server which is causing a folder naming or permissions issue.
Browse to “Plugins” in your WordPress Admin Area and delete all versions of the FooEvents plugin completely (don’t simply deactivate it). Then upload and activate the plugin again.
Alternatively, you can try manually deleting and uploading the FooEvents plugin via FTP but we strongly recommend that you first back-up your site files and database as a precaution.