This article includes suggestions and workarounds. Content may not be accurate for all use cases or represent best practices for the latest release.
Why am I receiving the message "Source Table Must Belong to a Spreadsheet data source, and can't be a custom table" when trying to save my Loader?
This message is shown when importing into a Modeled Sheet that contains splits. When it has splits, the Data Source should be a Spreadsheet data source. If you do not need the splits in the modeled sheet, and would like to load the data with a custom table or none-spreadsheet data source, you can remove the splits by navigating to the sheet from Modeling, choosing "Sheet Properties," and unchecking "Allow splits."
Another option would be to create a Spreadsheet data source to upload the data. This way, you can keep the splits in the modeled sheet.