I was getting the same error for a while too. It was very annoying.
It came down to my column names and making sure the columns were formatted for the correct data in Excel before importing it into Access. Once I made sure the column names were identical (including copying and pasting the formatting from/in Excel), I didn't
get the name errors. And once I made sure the formatting (date, text, yes/no boxes) was correct, the "Subscript out of Range" error disappeared and I was able to save the import process so I don't have to do it all over again if the source file gets updated.