Have seen several things to try, sadly none have worked for me. But they've seemed to work for others, so best of luck!
All of these mentioned turning off their firewall and rebooting after applying the fix.. something to keep in mind.
Option 1 - Open a Command Prompt (admin) and copy and paste this string - dism /online /cleanup-image /startcomponentcleanup
Option 2 - Change your Format in Control Panel > Region to English (United States)
Option 3 - Open a Command Prompt (admin) and paste the following
reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsStore\WindowsUpdate" /v AutoDownload /t REG_DWORD /d 4 /f
As far as Option 3 goes, a MSFT Mod replied to the guy that said it worked for him with the following
"Glad to know that you were able to fix your problem through this workaround. The Store in Windows Technical Preview (Build 9926) does not support manual updates of apps. In case you turned off automatic app updates during the setup, you'll be unable to update apps manually. Thanks for trying this and sharing the result."
I'm pretty sure I chose not to automatically update during setup, so that may be my issue. Again, none of these have worked for me, but others have said that they've helped. Best of luck!