Blank screen when trying to add missed stock sales

These are caused by a networking disconnect even when using the Desktop Product. 

Check to make sure you have a good, strong internet connection. If you are using a vpn, you might need to temporarily disconnect it. Same with anti-virus software. 

This didn't solve the problem. I've also rebooted my modem/router, restarted my laptop and software several times. We'd like to finish our taxes. How do we resolve this problem?

Prior to resuming work on our taxes today, the software applied updates. Could the updates be buggy?

If you still are not able to solve this, please call TurboTax Customer service.  Here is a link:  Turbo Tax Customer Service