Cannot install macOS Big Sur Beta

App & System Services Core OS
RobChag OP
Created Aug ’20
Replies 61
Boosts 0
Views 16k
Participants 46
Hello all,
I'm trying to install Big Sur beta and I face the same problem every time - after the installer is downloaded, installation starts and when the progress bar reaches 12 minutes installation interrupts with an error message "An error occurred installing macOS. You can try again to complete the installation".
I encounter the same problem starting from Beta 3, then Beta 4 and now the Public beta.
I performed SMC reset and even complete reinstall of macOS Catalina with no avail.
Would appreciate any help or ideas.
My system is 15" MacBook Pro (15,1) running macOS Catalina 10.15.6.
Replies  61
Boosts  0
Views  16k
Participants  46
Amxzingly OP
Nov ’20
Also want to try it out for fun. 2018 MBP, 13” 512 SSD w/ 8GB

Same message just at the 12 min mark.

Edit: Just tried again and noticed a jump from 12 minutes to 10 minutes right before the error message.
1
Nugget OP
Nov ’20
Same issue here on a MBP 16" with Dev RC 2. Same symptoms as everyone else.
1
Apple4Days OP
Nov ’20
Same issue here, jumps from 12 to 10 minutes. Will try reviving the T2 chip when the USB-C to USB-A cable comes in on Friday (hopefully the public release tomorrow will fix it).
0
JerryJnr OP
Nov ’20
Same problem here MBP13 2020
0
rockbmi OP
Nov ’20
Same issue here, 16" MBP. I have also Restored the firmware on the Apple T2 Security Chip and still getting the same error.

0
kmcbride OP
Nov ’20
A workaround is to enter this into the Terminal prior to running the installer:

Code Block bash
sudo nvram IASUCatalogURL=https://swscan.apple.com/content/catalogs/others/index-10.16seed-10.16-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

4
rockbmi OP
Nov ’20
Hi, what is that, what does it do?
0
JerryJnr OP
Nov ’20
Thanks that fixed it, what did it do?
0
BradleyHunt OP
Nov ’20
This also worked! Thanks 👍🏽
0
Jblank1074 OP
Nov ’20
Didn't work for me. I copied and pasted it, it asked for my password, I supplied that, re-ran the installer, same error at the same time. Did I do something wrong?
0
kh4inguyen OP
Nov ’20
Hi all,

I fixed this by:

  • Open Terminal. Paste and enter: 

Code Block 
sudo nvram IASUCatalogURL=https://swscan.apple.com/content/catalogs/others/index-10.16seed-10.16-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

You may need to enter 2 time if you got the error.

After that, rerun the installer --> It worked.

After done upgrading, you should update the nvram back:

Code Block 
sudo nvram -d IASUCatalogURL


Source: mrmacintosh.com/big-sur-11-0-1-rc2-full-installer-an-error-occurred-installing-macos
2
GianniV OP
Nov ’20
Hi @kh4inguyen, do you know if that solution works even installing Big Sur from USB from boot? Thanks
0
GianniV OP
Nov ’20
Hi the last suggestion fixed the problem. It works even with boot USB for clean installation. Thanks.
1
lucianafbohnert OP
Nov ’20
Disabling the Gatekeeper helped me after I encountered another problem after this one
0
samihaija OP
Nov ’20
I was getting an error installing it via App Store. However, this worked for me. After I tried (and failed) to install it from App Store, I found that I have a new Application:

Code Block 
/Applications/Install macOS Big Sur


I right-clicked that, clicked "Show Package Contents", and navigated to Contents -> MacOS and I double-clicked InstallAssistant.

I was able to install it from there
0
Cannot install macOS Big Sur Beta
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