Issue:

Jira cloud-to-cloud migration blocks when the board has an invalid/deleted filter. Such boards can't be corrected from the UI as they become inaccessible.
For S2C migration, customer can correct the entries in the DB by following the article: Jira Cloud Migration Assistant (JCMA) Error: The board is referring to a non-existent saved filter. However, for cloud-to-cloud, they need to contact Atlassian support.

Suggestion:

Ability to correct such boards from the UI.