My issue may have nothing to do with the update, but immediately after updating to V27, my OData APIs stopped refreshing in Excel.

hougaard Answered question 3 days ago
Check if your app is published and installed, if not, re-publish from the Simple Object Designer.
hougaard Posted new comment 3 days ago
The error is saying that you already have APIs called sales_Cr_Memo_Headers and vendors (either in this app or another app).
Do you have more than one app installed from SOD?
Only one instance of SOD is installed.
However, I do have an extension (which I despise) called Progressus. Is it possible that has fields named ‘sales_Cr_Memo_Headers’ & ‘vendors’ already?
Just to be clear, I’m not talking about SOD itself, but the app you created with SOD.
Progressus is in another publisher and group, so it’s shouldn’t conflict.
The app is installed with symbols updated, but not published.
It fails to publish with 5 warnings and 2 errors. The 2 errors are:
src/API/sG2025Sales_Cr_Memo_Reporting.APIPage.al(12,5) Error The EntitySetName ‘sales_Cr_Memo_Headers’ is already being used. The EntityName and EntityNames property values must be unique.
src/API/sG_2025VendorCOI_Reporting.APIPage.al(12,5) Error The EntitySetName ‘vendors’ is already being used. The EntityName and EntityNames property values must be unique.