There are now multiple threads running on this issue. No fixes or "workarounds" have yet been posted (other than reduce your machine to bare metal and start over w/o AV - which doesn't work).
<https://ttlc.intuit.com/questions/4572603-turbotax-premier-on-windows-10-pro-1809-is-constantly-rand...>
<https://ttlc.intuit.com/questions/4584656-i-have-turbotax-2018-deluxe-and-it-keeps-crashing>https://ttlc.intuit.com/community/Get-your-taxes-done-using-TurboTax/TurboTax-Deluxe-2018-crashes-co...
Good luck to all
