When trying to import, have you seen the following Import Error?
"Cast to date failed for value "Invalid date" (type string) at path "releaseDate""
If so, this means you need to format your Release Date (+ any other Date based) column in your Excel file.
To do this please select all of your Release Dates, alt click and select 'Format'.
From there, please select a Date format that matches both your data and the Date Format you entered into the Import Template.
The key consideration you should be aware of - make sure whatever Date format you choose does not include a '*' asterisk. This is normally the cause of any Date based issues.
Once ready, save the Excel and attempt a New Import. Any Date based issues should now be resolved.