This version of macOS 11.2 cannot be installed on this computer.

I am getting a notification saying "This version of macOS 11.2 cannot be installed on this computer." and even when I go to software updates, it says no updates available. Please contact me with some help.

I was given this computer by my boss. It is current running OS X Yosemite Version 10.10.5. iMac (27-inch, Late 2013), Processor 3.5 GHz Intel Core i7, Memory - 16 GB 1600 MHz DDR3.

Can someone please help me update to macOS Big Sur? It will not let me download is from the App Store because its sending me a notification saying "(null) can’t be installed on “Macintosh HD” because OS X version 10.14 or later is required."

Please let me know what to do. Thanks!

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