Hello.
Magento import tool is very strict to structure of the file. Columns can be sorted in any position, however, you have to stick to the list of required for import columns (their headings have to be the same as database names) and values in them.
Here is the article enumerating mandatory fields and details within them -
https://www.mag-manager.com/useful-articles/tipstricks/required-csv-file-values-for-error-free-magen...
Moreover, sometimes even negatively exported file does not suit to import it back. Editing the file you have to make sure that it is re-saved with UTF-8 without BOM encoding.