After afresh install, every subpanel on every module is empty. I have create an account and associated a Contact to that account but the Contacts subpanel show the title and the expand/contract double arrows but no content. All standard subpanels show this.
I believe permissions are correct and have rebuilt relationships and Quick Repair. Still nothing.
I copied the include/Subpanel directory from a 7.8.7 instance and now the subpanels are back and looking correct.
For reference, the changed files are
SubPanel/SubPanelDefinitions.php
SubPanel/SubPanel.js
SubPanel/SubPanel.php
SubPanel/SubPanelTiles.js
SubPanel/SubPanelTiles.php
SubPanel/SubPanelViewer.php
SubPanel/tpls/SubPanelDynamic.tpl
If you go to your system settings and disable Collapsed Subpanels they’ll work.
The author of the commit I referenced updated the SuiteP theme to handle his commit but not the legacy themes. Reverting SubPanelTiles.php to the previous version fixes the issue for now. I’ve confirmed that reverting the async loading commit doesn’t fix this.