can`t open storyboard on stable version Xcode

The document “Main.storyboard” requires at least Xcode 11.0. This version does not support iOS 13.0 system colors. Open this document with at least Xcode 11.0.

solved

open the storyboard as source code and first delete the lines:

<capability name = "iOS 13.0 system colors" minToolsVersion = "11.0" />

and everything where there is

cocoaTouchSystemColor

And then in the Interface builder to restore the desired colors.

thnx for Russian Stack Overflow https://ru.stackoverflow.com/a/992148/322338

In my case I had to delete this line:

<capability name="collection view cell content view" minToolsVersion="11.0"/>

And then replace all appearances of collectionViewCellContentView with view.