In Recovery, I reinstalled Sierra without erasing the disk.

Safe mode didn't bypass the point after login where the blockade happened, so it wasn't of use.

None of the errors I could find helped diagnose the problem.

After exiting into an interactive session, the same spinner issue cropped up. I booted into single-user mode and used the command-line tools to check for problems, and again, nothing emerged.I could boot into Recovery (Command-R after startup or restart), so I booted into it and ran Disk Utility.I went through a litany of options, including, after asking for advice on Twitter, ones I hadn't considered: Without the software installed, something else still triggered this slightly different behavior. I contacted the former developer and followed his instructions to use Recovery and Terminal to remove all relevant files, but that didn't solve this problem. In that case, the spinner would appear and disappear, but no cursor, and much more rapidly. I'd had a similar sort of problem crop up once during beta testing for software that I don't want to mention the name of, as the issue was resolved for those of us on the cutting edge and the particular release of software is no longer in development. When it finishes restart your Mac and test again for operation. Select your startup volume (usually named 'Macintosh HD') and click the Repair Diskbutton.

At the Mac OS X Utilitiesscreen, select Disk Utility. Officially, the macOS Human Interface Guidelines refers to it as the spinning wait cursor, but it is also known by other names, including the spinning beach ball, the spinning wheel of death, the spinning beach ball of death, or the ferris wheel of death. This would recur over and over for hours. After entering my account password, my Mac showed a white progress spinner that uses 'spokes'-the kind of spinner you usually see at shutdown-would appear for several seconds, then disappear, replaced with a cursor that couldn't be moved with the trackpad. A few days ago, after my 12-inch MacBook running the latest Sierra became sluggish, I restarted.

Mac os 10.12 wheel