Hi Willas,
Sorry for the delay in anyone getting to you.
Can you tell me the following:
1) WordPress Version
2) MarketPress Version
3) Any Plugins you have installed and activated.
4) What you were doing when you got the white screen – had you just activated? Added a product?
Also, if you know how to check your error logs and can tell me what error you’re getting that would help too. I’ve written a post about how to check your error logs here: https://wpmu.org/your-complete-guide-to-troubleshooting-wordpress/
Thanks!
Siobhan