fix: import summary text (#2772)

Updates the text on the import summary shown on partial imports.

src/library-authoring/import-course/messages.ts

@@ -295,7 +295,7 @@ const messages = defineMessages({
     id: 'library-authoring.import-course.import-details.import-partial.alert.title',
     defaultMessage: '<p>{percentage}% of Course {courseName} has been imported successfully.'
     + ' Imported Course content can be edited and remixed in your Library, and reused in Courses.</p>'
-    + '<p>Details of the import, including reasons some content was not abled to be imported are described below</p>',
+    + '<p>Details of the import, including reasons some content was not imported are described below</p>',
     description: 'Body of the import details page when the migration is in partial import.',
   },
   importPartialReasonTableBlockName: {

src/library-authoring/import-course/stepper/ImportStepperPage.tsx

@@ -40,7 +40,9 @@ export const MigrationStatus = ({
       for (const libraries of Object.values(migrationInfoData)) {
         // The map key in `migrationInfoData` is in camelCase.
         // In the processed map, we use the key in its original form.
-        result[libraries[0].sourceKey] = libraries.map(item => item.targetKey);
+        if (libraries.length !== 0) {
+          result[libraries[0].sourceKey] = libraries.map(item => item.targetKey);
+        }
       }
     }
     return result;