Made the following changes in flickr-justified-gallery-settings.php:
Changed Lines 115-116 from
$fjgwpp_provideColorbox_saved = fjgwpp_getOption('provideColorbox', $fjgwpp_provideColorbox_default);
$fjgwpp_provideSwipebox_saved = fjgwpp_getOption('provideSwipebox', $fjgwpp_provideSwipebox_default);
to
$fjgwpp_provideColorbox_saved = (int)fjgwpp_getOption('provideColorbox', $fjgwpp_provideColorbox_default);
$fjgwpp_provideSwipebox_saved = (int)fjgwpp_getOption('provideSwipebox', $fjgwpp_provideSwipebox_default);
Lines 174 – 175
if (isset($_POST["fjgwpp_provideColorbox"])) $fjgwpp_provideColorbox_saved = $_POST["fjgwpp_provideColorbox"];
if (isset($_POST["fjgwpp_provideSwipebox"])) $fjgwpp_provideSwipebox_saved = $_POST["fjgwpp_provideSwipebox"];
to
if (isset($_POST["fjgwpp_provideColorbox"]))
$fjgwpp_provideColorbox_saved = ((int)$_POST["fjgwpp_provideColorbox"] != 0) ? 1:0;
else
$fjgwpp_provideColorbox_saved = 0;
if (isset($_POST["fjgwpp_provideSwipebox"]))
$fjgwpp_provideSwipebox_saved = ((int) $_POST["fjgwpp_provideSwipebox"] !=0) ? 1:0;
else
$fjgwpp_provideSwipebox_saved = 0;
Now it works…