A common source of trouble with this type of import is not setting up the correct found set before you import. With the wrong found set in place, data that should update a matching record might be used to attempt creation of a new record and that might cause validation errors if you have unique values specified on a field to prevent duplicates.
Not only do some forget the needed Find or show all records to set up that found set, but it's also possible to create this problem by using a layout based on one occurrence of the target table to set up the found set but then choosing a different occurrence of the same table when importing records. Setting up the found set in one window and importing into a different window can also produce this mis match.
If that's not the issue, you need to look at the validation settings and your data to see what might be causing this. Sometimes it is useful to import into an intermediate table that does not have any field validation set up so that you can validate the data via script before you import.
Hi Phil. I am indeed using an intermediate table with some validation on the fields. I'm sure those are what are creating the errors. I thought there would be a log of some sort that shows what the errors are, is there no way to see this after import?
AFAIK, there is no such log. That's why I am suggesting other ways to resolve the problem--including an intermediate table with NO validation set up on its fields.