darktable (Windows 10) has lots its Alt+1, 2, 3 keys--I cannot zoom in (enlarge an area)

Since early January, I’ve been unable to get darktable to work on this refurb Windows 10 slow, annoying machine–but I got it going at last, last night. I wish I knew how exactly. So at last I got my RAW files off my DSLR. But whereas I used to hold Alt and the 1 2 or 3 keys to zoom in, now it says “Alt + 1” (etc.) not assigned." I want to see how, for example, how sharpening is looking.

Hi & welcome! Have you checked the preferences or your config files to see what hotkeys are mapped to what function? The 3.8 update implemented completely new hotkey control.

No, paperdigits. How would I do that?

Click the gear icon near the upper right of the image, then see darktable 3.8 user manual - shortcuts

Thanks for that, although I haven’t yet found the manual at the cog either in lighttable or darkroom.