Issue Summary:

Some customers are experiencing temporary unavailability of app custom content. This has been seen to occur when major or minor version update is installed for an app in which custom content was migrated from Connect to Forge (see Migrate custom content from Connect to Forge).

Following the update, requests to the custom content APIs may return a 404. This issue persists until internal caches expire, after which the custom content becomes available again.

Atlassian is currently working to rollout a fix for this issue.

Workaround

Custom content should become available again after a window of 1 - 10 minutes.