diff --git a/include/simpleplugin/class_simplePlugin.inc b/include/simpleplugin/class_simplePlugin.inc
index dde927f0cf17615434cc85941e3aa79fb5fcb1e2..d515d1835c28c508c78bec35380f5a6be547fd91 100644
--- a/include/simpleplugin/class_simplePlugin.inc
+++ b/include/simpleplugin/class_simplePlugin.inc
@@ -2063,6 +2063,11 @@ class simplePlugin implements SimpleTab
    */
   function foreignKeyCheck (string $field, $value, array $source)
   {
+    // In case of SetAttribute, value is an array needing to be changed to string.
+    if (is_array($value)) {
+
+      $value = $value[0];
+    }
     return $this->attributesAccess[$field]->foreignKeyCheck($value, $source);
   }