1. Problems

The errors reported by unity2020 during play scene are as follows:

Assets\Standard Assets\Utility\SimpleActivatorMenu.cs(11,16): error CS0619: ‘GUIText’ is obsolete: ‘GUIText has been removed. Use UI.Text instead.’

2. Solutions

Double click the red box in the figure above, unity will automatically jump to visual studio and modify the following two positions,

Amend as follows:

Then save.