I experienced this problem with ArcMap/ArcCatalog 10.6.1 many times. Deleting or adding new attribute field to a feature class (using ArcMap or ArcCatalog) in File Geodatabase will make all the data in this feature class corrupt (all data disappeared, the feature class become invalid ), this happened many times. It seems some fields names (even if they are reasonable names) are not acceptable by ArcCatalog, but I do not understand why the data corrupt and disappeared. Anyone knows what happened and any workarounds?
