A form section may lose its sys_ID-linked system UI section after an instance is upgraded or a plugin is repaired.
Steps to Reproduce
1. Create a scoped-app1 with table x and form x.
2. Create second scoped-app2 and add a tab(ui-section) on form x.
3. Upgrade/repair scoped-app1.
4. Form x is losing tab (ui-section added by scoped-app2).
5. UI section still exist, somehow losing relation between form section and UI section.
After carefully considering the severity and frequency of the issue, and the cost and risk of attempting a fix, it has been decided to not address this issue in any current or near future releases. We do not make this decision lightly, and we apologise for any inconvenience.
When multiple plugins collaborate to produce what seems to be a single module or object like a form layout, it is not supported to repair just one of the contributing plugins. All of the collaborating plugins need to be repaired in the order they are processed during an upgrade.
Related Problem: PRB1326773