iphone could not be updated. error (75).067E.004B

Update from what to what version? Do you have enough free storage available? If not from the immediately previous version, need 7-8GB free at minimum.

First my iphone started to give "error could not update mobile data network" errors every now and then after which I had to reboot my phone, endure a boot loop for a while every now and then but I always managed to get it fixed even if it took 30 mins, but today it got permanently stuck just as I desperately needed it to get my Final year school results in the middle of a pandemic. Anyway I tried updating it through itunes and got an error 9 which got it out of the bootloop but stuck in recovery mode, now I cant even restore the phone due to error 75 which no one knows what it's about so IOS 14 just bricked my phone.

I also got this error message while trying to update my 2017 iPad Pro using my Macbook Pro with Big Sur via Finder with lightning cable. I've tried two cables and two different USB ports.