Black screen after login, desktop icons appear, no dock, no desktop image

[TK-421]

After login, which is normal with a background desktop image, my iMac opens the desktop screen with a flickering black/desktop image background. The desktop icons appear, but I can't access the dock. I can select things OK and shut down as normal. Sometimes after restart, it launches as normal. Sometimes I have the same issue. I have tried resetting the NRAM/PRAM and reset of SMC, these seem to work for a while but the problem occurs again. I also checked my startup items and removed 'Acrobat Collaboration' again, OK for a while, but the problems is still occuring.

My iMac is running Big Sur 11.7.9, it's a Retina 5k, 27-inch 2017. Processor 3.8GHz Quad-Core Intel i5.

Many thanks.

 

[baker_rrr]

It sounds like a graphics or system issue, maybe something with macOS or a conflicting app. Since resetting NVRAM/PRAM and SMC worked for a bit, try starting in Safe Mode by holding Shift during boot and see if the problem still happens. If it doesn’t, it could be a third-party app causing it. You might also want to try reinstalling macOS or updating to the latest version, which could fix any bugs causing the flickering.

 

[TonyAguila]

After login, which is normal with a background desktop image, my iMac opens the desktop screen with a flickering black/desktop image background. The desktop icons appear, but I can't access the dock. I can select things OK and shut down as normal. Sometimes after restart, it launches as normal. Sometimes I have the same issue. I have tried resetting the NRAM/PRAM and reset of SMC, these seem to work for a while but the problem occurs again. I also checked my startup items and removed 'Acrobat Collaboration' again, OK for a while, but the problems is still occuring.

My iMac is running Big Sur 11.7.9, it's a Retina 5k, 27-inch 2017. Processor 3.8GHz Quad-Core Intel i5.

Many thanks.

If I were in your situation, I would try updating macOS to the latest version that your iMac is capable of running, which is macOS Ventura 13.7.3 (22H417). Of course this assumes that you have up-to-date Time Machine backups first. This also assumes that your apps, especially the ones that you rely on regularly, are all compatible with Ventura. If you don’t wish to update to Ventura, you should at least download and reinstall the latest macOS Big Sur installer which I believe to be 13.7.4 (23H420). This seems to be the most prudent step for you, but keep in mind that a lot of improvements have been introduced in the latest macOS version available to you. Let me know if you need help in downloading the installer file.