When logged in as Administrator in a Windows 10 or 11 machine, when you try to add a shared printer, you get the error:
That didn't work. We can't install this printer right now. Try again later or contact your network administrator for help. Error: #740.
The underlying problem is this: Error 740 means: "The requested operation requires elevation".
This is a problem as you are already logged in as Administrator. So the solution is to start the "Add Printer Wizard" as Administrator. To do this:
rundll32 printui.dll,PrintUIEntry /il
Go through the "Add Printer Wizard" as normal. This time, it will work without error.