diff --git a/app/resources/locales/en_US/default.po b/app/resources/locales/en_US/default.po
index 4893d51d..4caee09a 100644
--- a/app/resources/locales/en_US/default.po
+++ b/app/resources/locales/en_US/default.po
@@ -294,6 +294,9 @@ msgstr "Incorrect arguments provided to {0}"
 msgid "match.er.attr.req"
 msgstr "Required attribute {0} not found in request"
 
+msgid "match.er.attrmap.unknown"
+msgstr "Unknown Attribute Map {0}"
+
 msgid "match.er.bl.line"
 msgstr "Error at line {0}: {1}"
 
diff --git a/app/src/Controller/AttributeMappingsController.php b/app/src/Controller/AttributeMappingsController.php
index 65eda7c6..4cbd9ce9 100644
--- a/app/src/Controller/AttributeMappingsController.php
+++ b/app/src/Controller/AttributeMappingsController.php
@@ -50,7 +50,7 @@ public function install() {
       
       $this->Flash->success(__('match.rs.AttributeMappings.install'));
     }
-    catch(Exception $e) {
+    catch(\Exception $e) {
       $this->Flash->error($e->getMessage());
     }
     
diff --git a/app/src/Model/Table/AttributeMappingsTable.php b/app/src/Model/Table/AttributeMappingsTable.php
index 26c85f8f..ccb31867 100644
--- a/app/src/Model/Table/AttributeMappingsTable.php
+++ b/app/src/Model/Table/AttributeMappingsTable.php
@@ -62,10 +62,15 @@ public function initialize(array $config): void {
    * 
    * @param  int    $attributeMapId Attribute Map ID to install into
    * @param  string $mapping        Mapping to install, currently only "nicknames.en" is supported
+   * @throws \InvalidArgumentException
    * @throws \RuntimeException
    */
   
   public function install(int $attributeMapId, string $mapping) {
+    if($mapping != 'nicknames.en') {
+      throw new \InvalidArgumentException(__('match.er.attrmap.unknown', $mapping));
+    }
+
     // For now, we assume this is the CSV file from this project:
     // https://github.com/carltonnorthern/nickname-and-diminutive-names-lookup
     $infile = fopen(ROOT . DS . "vendor" . DS . "nicknames" . DS . "names.csv", "r");