I can no longer view my feature classes within a feature dataset... I don't know why... I've attached the ArcCatalog version 10.7 which can still see the feature classes, but ArcPro 2.6 can no longer see the feature classes. I had no issues with ArcPro 2.5.2. Pro 2.6 just shows the feature dataset but shows it empty, with no feature classes.
Thomas, did you find a solution to this. I am having the same problem. The feature classes are still there, still visible in ArcCatalog and ArcMap but only the feature dataset is now visible in ArcGIS Pro. Thanks