Contradictory to what the official website says here: https://docs.krita.org/File_Menu, the opening of Icon files does not work and the Saving/Exporting only seem to work partially. Dragging them into the Krita window works nothing better than selecting Open from the File menu. In the Save and the Export dialog, "*.ico" IS listed under "All supported formats", yet not separately and DOES work however. I've just checked again, nowhere (not on the site, nor in the actual program) does it explicitly say that Krita should be able OPEN .ico-files... What is the point in that though? I can literally save a file, try to open it and Krita will not know what to do with it and call it "unknown"... This is somewhat retarded in my opinion. I see why this could be intended. Since .ico-files usually store multiple versions of an icon in one file, opening them could be considered more complicated than saving them. But again, this shouldn't be preventing me from opening something I just saved. Please actually fix this bug and add the feature in, DON'T JUST REMOVE THE ARTICLE ON THE WEBSITE, please. Thanks, it would help a lot if you could find a solution to this, maybe even another dialog for opening .ico-files in which the user can select the version/size of the icon.
Krita can save to .ico, but cannot load it. That is what the manual says, too: "List of Formats that Krita can Save to". So the manual is correct. I checked and I could save an image as .ico, so that works, too. We have currently no plans to implement loading .ico files at all: someone who thinks this is an important file format would have to volunteer for working on that.
Checked on our current master branch (commit 6a4ed9a5a9). Our QImageIO plugin covers all possible import cases (1, 4, 8, 24 and 32-bit). It is able to export 32-bit icons. Due to Qt limitations, it only reads one icon at a time.