Cannot install macOS Big Sur Beta

seeing exactly the same
have tried the dev and public betas

Same here with the public beta

• I tried to install on external SSD

• Encountered this issue

• Force Rebooted my Mac

• Saw An error occurred installing macOS. You can try again to complete the installation"

The issue persists with dev beta 5.
As suggested by dcas and rb69 this has something to do with BridgeOS update. Did anyone succeeded finding a workaround?

Same issue

Public bete 5: Same problem

Same issue here. Tried all the ideas anyone has suggested when the issues of installing Big Sur. No help.
MacBook Pro (13-inch, 2020)

Same problem here.

Was on Public Beta 1 on Macbook 2015 running smoothly, attempted to update to Beta 5 (public beta 2), crashed while installing, the beta is now still present in system preferences however download won't complete, nor will install ever occur.

Have tried via terminal command line - no different.

There’s a bit of download to be down while the installation is in progress. Check below:

Aug 24 13:27:27 Shiham-MBPR osinstallersetupd[2234]: Retrieving 4 packages (1.193 GB)
Aug 24 13:27:27 Shiham-MBPR osinstallersetupd[2234]: Started downloading package com.apple.pkg.BridgeOSUpdateCustomer (http://swcdn.apple.com/content/downloads/33/25/001-36812-A_S039U0DYM5/3g8uq0l1rzpxhuk8z4woz38c8k4vv0iuoi/BridgeOSUpdateCustomer.pkg)
Aug 24 13:44:19 Shiham-MBPR osinstallersetupd[2234]: Retrieved package com.apple.pkg.BridgeOSUpdateCustomer (http://swcdn.apple.com/content/downloads/33/25/001-36812-A_S039U0DYM5/3g8uq0l1rzpxhuk8z4woz38c8k4vv0iuoi/BridgeOSUpdateCustomer.pkg)

A similar problem on my MacBook Pro 15 2018 release, and on MacBook 12 everything went without problems, apparently the problem is related to T 1/2 security chips.

I managed to fix this and the 'Cannot install error'

Using a combination of the following (I don't know which worked)

1. Reset PRAM

2. Disable Filevault

3. Boot into Recovery and enable Startup Security

4. Use sudo sh -c "softwareupdate -ia" via terminal

Macbook 2015, Previously unable to restart with kernal panics and unable to install/download Public Beta 5

The "fix" is to restore BridgeOS on the T2. This can be done using a 2nd MacBook that has a USB-C port, downloading Apple Configurator 2 software and connecting the 2 laptops with a USB-C cable. The MacBook that needs restored has to be put into DFU mode. It's useless to take it to a Genius Bar. All they will do is keep it for 6 days and run diagnostics on it. If you can't do this yourself, you should just wait until Big Sur final is released. Hopefully by then the issue will be resolved

I can confirm that restoring (or rather, reviving) T2 BridgeOS resolves the issue.

I shall note, however, that restoring T2 BridgeOS is delicate and risky procedure. I personally had no issues whatsoever, but I've read multiple reports of failed procedure resulting into bricked hardware. If anything goes wrong, it guarantees a trip to Apple service as there's no DIY solution available.

If that's your only or your main machine I strongly recommend waiting for subsequent build or even the GM where this issue will most likely be fixed by Apple.

This being said, detailed instructions on reviving or restoring the BridgeOS can be found here: https://support.apple.com/en-gb/guide/apple-configurator-2/apdebea5be51/mac

I used the solution suggested by macguy59 and RobChag, it solved the problem with the error at 12 minutes of installation, but after the initial installation, the system asks to restart the PC, I get an apple, the installation starts, the screen blinks and boots normally in the OS Catalina, tried to put on a clean Catalina OS, the problem persists.

Today I succeeded in installing MacOS Big Sur 11.0 Beta (20A5354i) on my MacBook pro 16".

The public beta is working now. Will try the developer beta as well.