I know there have been changes to transformation. I have been trying to troubleshoot this error upgrading from 3.4. to 4. The error is coming when using a sitemap.
[ERROR] [ui.internal.items.ItemUIRegistryImpl] - transformation throws exception [transformation=org.openhab.transform.map.internal.MapTransformationService@31c5bf51, value=-]
org.openhab.core.transform.TransformationException: Target value not found in map for '-'