UPDATE: we were able to resolve the missing custom hierarchy setting default record after waiting the required minimum 5 day interval to “re-refresh” our affected Sandbox. With a goal of getting a complete copy of custom settings records, we took the step of removing all objects that had zero records from our sandbox template prior to the refresh. I’m not sure if reducing the number of objects referenced in the sandbox template was the direct cause of getting a complete copy of the settings, but it seemed to work.
HOWEVER - the “Stale Session Exception” was encountered again in the refreshed sandbox when trying to access the Skuid Central, Skuid Settings and Themes tabs within the SKUID app. Also, we noted that the Pages and Page Assignments tabs were showing standard Salesforce pages instead of the SKUID visualforce pages. Bummer!
The above observations pointed to missing metadata on the Skuid tabs and custom objects. We determined that the Page and Page Assignment objects were missing the appropriate Visualforce page content source settings, so we were able to manually override them as shown below:
This restored access to the page and page assignment tabs - groovy!
BUT - the custom Skuid Visualforce tabs could not be fixed in a similar way as they are managed and I could not figure out a way to override the tab content to point to the appropriate Visualforce pages:
Skuid Central Tab:
Skuid Settings Tab:
Skuid Themes Tab:
For now, the missing tab content assignments are inconvenient, but we can work around this issue as the Skuid Central, Skuid Settings and Themes Visualforce pages are accessible after navigating to the Pages or Page Assignments tabs.
If anyone knows of a way to manually set the custom tab content Visualforce page references, please let me know!
In the meantime, I will be following up with Salesforce support to see if the missing metadata problems that arose during or partial sandbox refresh can be addressed in a future patch or major release. To me, this seems like a bug in the Spring '16 Salesforce release as my expectation would be that metadata for installed packages should be completely copied during any sandbox refresh whether it be a dev, partial copy or full copy sandbox.