I get the message: "Support Ending for Intel-based Apps", OR Screenwriter needs to be updated. The developer of this app needs to update it to work with this version of macOS

When I launch Screenwriter on MacOS Tahoe 26.x I get the message:

Screenwriter needs to be updated. The developer of this app needs to update it to work with this version of macOS. Contact the developer for more information.

You can safely ignore this message.  This is Apple warning users that in September of 2027, they will drop support for Rosetta 2, which is required to run Movie Magic Screenwriter on Apple Silicon.

However, this next version of Screenwriter (6.8) -- due out in May 2026 -- will be fully Apple-Silicon compatible -- meaning it will run natively on Apple's M1/M2/M3/M4/M5 processors WITHOUT Rosetta 2.

And -- it's fast.  Very fast!

Screenwriter will continue to be produced as a universal app -- meaning it can run on both Intel processor Macintosh hardware and Apple Silicon for a few more releases, but Apple has made it clear that backwards Intel compatibility must come to an end in September of 2027.

So to reiterate: if you have a relatively new Apple Macintosh (MacBook Pro, MacBook Air, MacBook Neo, iMac, Mac Mini, Mac Pro, and Mac Studio, then it will have an Apple Silicon processor, and we will support that natively.

So you don't need to do anything.  Each time you run Screenwriter, it will run "Check for Update" (or you can use Screenwriter's HELP > Check for Update command at any time.  You will be automatically notified when a new version is available.