A row is counted as an error when:

• the name or contact cell is empty;
• the row has a different number of columns than the header (an extra comma inside a name, for example);
• the email address already exists in your Contacts – duplicates are skipped rather than re-created (when importing from a list, the existing contact is still linked to the selected lists).

Also check that the first header cell is exactly name and the second contact; other column names are ignored. Fix the rows and re-upload – already-imported rows will simply show as errors the second time, which is harmless.