The Apple Support Community will permanently close on November 20, 2026. Starting today, the site will no longer accept new posts and is available in a read-only state.
You can continue to find trusted guidance and support on the official Apple Support site.
We want to thank the community members who have contributed their time and expertise to help others with their Apple products.
The Apple Support Community will permanently close on November 20, 2026. Starting today, the site will no longer accept new posts and is available in a read-only state.
You can continue to find trusted guidance and support on the official Apple Support site.
We want to thank the community members who have contributed their time and expertise to help others with their Apple products.
I received a software update from a well known site, one I use frequently and after initiating the update I got a prompt that the update was not compatible with my OS. I went to the apple support page and was told to run a diagnostic program (restart holding the "D" key. The result was a dozen screen and the following message: apple.com/support -3403D
My iMac appears to be frozen at this time. What to do?
iMac 21.5″, macOS 10.13
Hold down the power button on the iMac until it shuts down, restart in Safe Mode per Safe Mode Reset and then restart normally and re-test.
the result was a "frozen" screen...
error code -3403D
