Windows (Windows 2000, XP, Vista, 7, 8, 8.1, 10, and 11)
Go to the CrimsonNet.image file and right click it.
Go to “Open with”
Click “Choose another app”
If you are on 8, 8.1, 10 or 11, click “Choose another app” and then click “Choose an app on this PC”
If you are on an older version of Windows, pick an app directly.
Go to C:\Program Files (x86)\Scratch or the directory you installed Scratch 1.4 in.
Select Scratch.exe.
Press “Open/Choose”
Then go back to the CrimsonNet.image file and double-click it.
It should open in Scratch.
Note: MacOS 10.15 and later versions do not support Scratch 1.4's editor because it is a 32-bit app. All 32-bit apps had support dropped in MacOS 10.15.
Open a file once with a specific app
On your Mac, do one of the following
Drag the file onto the app icon in the Finder or the Dock.
Select the file in the Finder, choose File > Open With, then choose an app.
Control-click the file, choose Open With, then choose an app.
Open the .image file.
Permanently change the app used to open a file (recommended)
On your Mac, click the Finder icon in the Dock to open a Finder window.
Select the file, then choose File > Get Info.
You can also Control-click the file, then choose Get Info.
In the Info window, click the arrow (>) next to “Open with.”
Click the pop-up menu, then choose the app.
To open all files of this type with this app, click Change All.
(From Apple Support)
GNU/Linux (Debian installers (Debian, Ubuntu, Linux Mint, etc.) as well as RPM-based ones (Fedora, Red Hat, etc.) )
Follow the instructions for your distribution’s method of setting the MIME type (the thing that tells your GNU/Linux distribution which program to open a file).