diff --git a/src/lang/de.json b/src/lang/de.json
index c1ea7a2..391571e 100644
--- a/src/lang/de.json
+++ b/src/lang/de.json
@@ -198,7 +198,8 @@
     "DS4.RollDialogDefaultTitle": "Proben-Optionen",
     "DS4.RollDialogOkButton": "OK",
     "DS4.RollDialogCancelButton": "Abbrechen",
-    "DS4.ErrorUnexpectedHtmlType": "Typfehler: Erwartet wurde {exType}, tatsächlich  erhalten wurde {realType}",
+    "DS4.ErrorUnexpectedHtmlType": "Typfehler: Erwartet wurde '{exType}', tatsächlich erhalten wurde '{realType}'.",
+    "DS4.ErrorCouldNotFindForm": "Konnte HTML Element '{htmlElement}' nicht finden.",
     "DS4.RollDialogTargetLabel": "Probenwert",
     "DS4.RollDialogModifierLabel": "SL-Modifikator",
     "DS4.RollDialogCoupLabel": "Immersieg bis",
diff --git a/src/lang/en.json b/src/lang/en.json
index 6cd7c33..e1d15a5 100644
--- a/src/lang/en.json
+++ b/src/lang/en.json
@@ -198,7 +198,8 @@
     "DS4.RollDialogDefaultTitle": "Roll Options",
     "DS4.RollDialogOkButton": "Ok",
     "DS4.RollDialogCancelButton": "Cancel",
-    "DS4.ErrorUnexpectedHtmlType": "Type Error: Expected {exType}, got {realType}",
+    "DS4.ErrorUnexpectedHtmlType": "Type Error: Expected '{exType}' but got '{realType}'.",
+    "DS4.ErrorCouldNotFindForm": "Could not find html element '{htmlElement}'.",
     "DS4.RollDialogTargetLabel": "Check Target Number",
     "DS4.RollDialogModifierLabel": "Game Master Modifier",
     "DS4.RollDialogCoupLabel": "Coup to",
diff --git a/src/module/rolls/check-factory.ts b/src/module/rolls/check-factory.ts
index b0f007e..43d8efa 100644
--- a/src/module/rolls/check-factory.ts
+++ b/src/module/rolls/check-factory.ts
@@ -150,7 +150,9 @@ async function askGmModifier(
                             } else {
                                 const innerForm = html[0].querySelector("form");
                                 if (!innerForm) {
-                                    throw new Error(); // TODO: localize
+                                    throw new Error(
+                                        game.i18n.format("DS4.ErrorCouldNotFindHtmlElement", { htmlElement: "form" }),
+                                    );
                                 }
                                 resolve(innerForm);
                             }