MacOS high Sierra 10.13.4

I’ve gotten the message that the app isn’t optimized for 64 but tech. Please advise.
Thank you

Scrivener 2 is 32-bit so is not optimised for High Sierra, although it will run perfectly fine, so you can safely ignore the warning.

Scrivener 3 is fully 64-bit, however, so unless you have a reason for staying on Scrivener 2, I would recommend upgrading - Scrivener 3 is a paid update, available for $25 for users of Scrivener 2 (follow the “Upgrade from an Older Version” link on the “Buy Now” page).

All the best,

Thanks so much!

Eventually 32-bit apps won’t run anymore on MacOS (although no one knows when that is going to happen, and most likely Apple will alert with plenty of time). But my point is, since at some point one has to move to a 64-bit version, doing it sooner rather than later is probably best

Apple has made it quite clear that macOS 10.14 is that last OS to run 32 bit apps without compromises, so expect macOS 10.15, which is likely released in September 2019, to have issues with 32 bit apps - If they run at all.