"Failed to Import" message when clicking Cancel on the Alembic Import Message

When cancelling the importing of an .abc file, user receives a "Failed to Import" message, making it seem like something went wrong.

This doesn't occur when importing non-Alembic files.

1. Open QAGame in editor.
2. Click Import in the Content Browser.
3. In your build, navigate to Engine\Content\NotForLicensees\QA\Import_Test_Assets\AlembicAssets.
4. Select SceneTest.abc and click Open.
5. Click Cancel on the Alembic Import window.

RESULT:

User received "Failed to Import" message.

EXPECTED:

Import was cancelled, so no message should appear (just as it is with non-Alembic imports).

Why is this setup producing wavy shadows?