I've gotten the "Failed to load data. Error: Unexpected operation " error several times when I try to open an attribute in ArcGIS Pro v. 2.4.2 on Windows 10. I haven't been able to figure out any pattern to what is causing the error. I was able to load the attribute table for a dataset one minute and then a few minutes later I get the error when opening the table. I can select the feature and see the attributes in the pop-up dialog and the edit attribute panel. I have no pending edits, no definition query, or any other constraints on the data. Closing and reopening the project does not help.
Any thoughts or suggestions?