This is similar to https://jira.sakaiproject.org/browse/SAM-1383. Here are how to reproduce the issue:
1. In site A, create an assessment and release it to groups.
2. Export that assessment.
3. In site B, import that assessment.
4. Go to the setting page of the imported assessment. You will see nothing is selected in the "Release To" section.
The "Release To" should be set to the site.