Exist import with 'Add and Replace' option

Exist import with 'Add and Replace' option

I've been trying to do an exist import with Add-Replace option but not able to after so many attempts. See the error below. The existing table (Company Master-YE) has ~51k rows and the intended import file has ~35K. I'm trying to add and replace based upon two matching fields.

While I understand that this operation is somewhat resource-intensive and could take a while, I'm disappointed because I'm not able to do it at all.