Screenshot taking a very long time to appear on desktop
I have the same problem here. It seems to be a refresh problem. The file is actually there, it just doesn't show up. If I open a Finder window in the desktop folder the same problem happens. But I can verify it's a refresh problem because if I go to other folder and come back the file is already there. I have an iMac with a Fusion Drive. High Sierra doesn't convert it to the new APFS file system. I'm guessing it has something to do with that. My guess is that High Sierra is prepared for APFS and that APFS treats file refreshing differently from the earlier MacOS file system. So whatever signal it's expecting from the file system, it is not receiving.