ID 572023 - Sequence revision cannot be saved when missing the annotation asset

Problem summary
When sequence revision is missing an annotation asset annotation_asset_id = null, the sequence revision can not be saved.

Customer reported version
flix_6.6.2

Customer reported platform
windows10

Steps to reproduce

1)Go to a revision with panels and annotation.

2)In a network tab open the revision - (if it's revision 10, click on 10).

3)Open metadata and check the annotations. Take note of the id.

4)In the database, open the metadata table and find a row with the id from step 3.

5)Update the field_value of that row with null - then save.

6)Refresh the revision in Flix.

7)Make a change and try to save.

Expected behaviour
Sequence revision to be saved successfully.

Actual behaviour
Displays an error banner and the user can not save the revision.

Workaround
Find the panel with the problem annotation and replace or remove it.

Reproduced by support
Flix 6.6.2