The v20.0.3.24950 update also introduced several "quality of life" improvements that fundamentally changed how users interacted with the canvas. The "Undo" command was finally standardized to follow the modern industry convention of Ctrl+Z (or Cmd+Z) for multiple steps, eliminating the need for the cumbersome "Step Backward" shortcut. Additionally, the introduction of live blend mode previews allowed users to hover over options in the Layers panel to see instant changes, significantly speeding up the creative experimentation process.
If you're still experiencing issues with activation, you can try using a preactivation fix tool. These tools can help resolve issues with license validation and get you up and running with Photoshop. adobe photoshop cc 2019 v200324950 preactivated fix