dataset_too_large
What happened
A file is sent in parts, and the plan has to keep each part between the smallest and largest part size and the number of parts under the most allowed. A plan outside those is refused when the record is created, before any part is sent. The upload flow checks the file's size first and answers import_too_large.
What to do
Use a smaller file, or split it into several files.
Example
text
This file is larger than we can accept.The sentence above is what the upload screen shows for a file that is too large.