Reproduction

1. Create custom data type in Umbraco.
2. Create LeBlender with created data type in grid editor.
3. Create page and put LeBlender into this page like a new tab.
4. Create this page in tab "Content" and put to LeBlender some data.
5. Save and Publish created page.
6. Delete data type which has been created in step 1.
7. Create same data type according data type which has been created in step 1.
8. Add new data type to LeBlender.
9. Go to created page in "Content" tab. Now information(alias and Guid key) about data type which not exist in Umbraco comes to partial view which connected(It should be connected in step when LeBlender is created) to LeBlender.

If you try to get data type for rendering in preview, NullReferenceException occurs.

Expected result

Receiving of updated information to partial view about new data type was expected.

Versions

LeBlender - 1.0.8.4; Umbraco - 7.11.1