I have worked through all the suggestions and limitations from ESRI to the best of my understanding. My field names start with a letter, have no spaces, are less than 30 characters, and only letters and underscores. I have also made sure all my columns were consistently formatted: date, text, or number. Further, I have resaved using different filenames, and have copied the data to new workbooks in case of corruption. I have also restarted PRO as well as my computer.
I have 1391 rows, and 23 columns.
Is there a limit to the number of columns an imported worksheet might be allowed or potentially another issue I have not considered?
I have noticed that every time I copy the data to a new workbook, I get the error. When I take the new worksheet and make sure all the column formatting is consistent, I don't get the error, but the worksheet does not show up (image above). When I take that same newly created and column-formatted workbook, copy and paste it into yet another new workbook, the error returns, until I re-format the columns, etc, etc.
Due to data sensitivity, I can't provide an image example, but if necessary I will rename things to post.
I know https://gis.stackexchange.com/questions/312470 has previously been asked here, but no response was given, and that question is now deleted.
Note: I recently imported the same spreadsheet into MAP and it works just fine. While I'd like to exclusively use MAP as it has been so much easier to use for everything I do, I am trying to adopt ArcGIS Pro due to the phasing out of MAP support.