.... this is the likely issue with anyone with a blank page during the running of Desktop TTX software.
.......TTX should only be installed and run as an Administrator..not in some guest account without administrator privileges...but it's hard to know each person's exact setup.
1) right click TurboTax 2018 icon
2) Select … Properties
3) Select the Compatibility tab
4) In the "Settings" box … check the box to "Run this program as an administrator"
This has fixed the problem for a number of users now.