Due to a mistake, migration scripts for version 2021 R3 (2021.1.3.136; 2021.1.3.178) do not take into account changes in REST data source configuration.
After updating to version 2021 R3, all REST data sources configured in versions older than 2021 R1 will cease to function.
Data sources configured in 2021 R1/R2 will only return columns from a collection that have been manually selected, whereas previously they would load all columns without needing to select them individually.
For a data source to return columns from a collection again, unmark and mark the desired collection’s checkbox in the ‘Result’ configuration column. All simple type data types under the collection node should be marked automatically.
We are working on a permanent fix to this issue.
If you were planning on updating to version 2021 R3 and are using REST data sources, we recommend that you hold off until we publish a version that resolves this issue.