update to Big Sur
macOS Big Sur install stopped in - checking "null"
MacBook Air 13″, macOS 10.13
Question marked as
Have you attempted the download Big Sur more than once. If Yes, do to Applications Folder and if there is a New Application called " Install Big Sur " - Drag and Drop to Trash and Empty the Trash.
Big Sur download the error message can be misleading.
There are factors like poor Wifi connection, slow wifi connection, too many other people downloading at the same time and Apple Severs are overloaded.
Software on the computer interfering with the download process including AntiVirus software.
Running behind a VPN.
If via wifi too many Other devices using the wifi at the same time reducing the Bandwidth to your computer.
Best Results are via Ethernet Cable to Router