How to fix the error - The application "Sketch" can't be opened in macOS Sierra ?

You may have come across the error 'The application "Sketch" can't be opened' if you have tried installing an older version of sketch app on your macOS, provided that you have an older version of macOS installed. This error dialog may look something like shown below(following is the error dialog for a different application)

error dialog

Inorder to get rid of the issue, perform the following steps

1) First of all, open your terminal window and type in the following command

sudo xattr -rd com.apple.quarantine

type the command like shown in image

    add a space after the command

2) Now go to your folder containing the sketch app installation file. Now drag and drop the sketch app executable file into the terminal like shown below

Note that it already filled the command with the file path

Hit enter, then type in your password and again hit enter

3) Now try opening the Sketch app file by double clicking it, it should open properly