Slack - White Screen

Resolution

https://www.reddit.com/r/Slack/comments/q1g8kp/slack_app_blank_white_screen_on_windows_10/

When Slack opens in a White Screen the problem is either a Cache issue or a Hardware Acceleration issue. 

Mouse over the upper right hand corner and you will see the menu > Help > Select Troubleshooting > Clear Cache and Restart. If the White Screen appears again got Menu > Help > Troubleshooting > Toggle Hardware Acceleration > and Clear Cache and Restart again. 

Hover over the top left

This is the menu you can access with the white screen