My system had SAB, REAB and DAB 9.0 installed beforehand.
DAB 9.0.1 and RAB 9.0.1 installed without any errors.
SAB 9.0.1 gave me this error twice on two tries.
System is Win10x64 21H1, fully up to date with patches
On the second install, after the previously attached error, I had the option to select Next, so I did.
The install had another error near the end of install, so I cancelled the second install.
Then I uninstalled SAB 9.0, rebooted, and tried to install SAB 9.0.1 again , and it worked that time.
Mike, it appears that atcuf32.dll is part of BitDefender AntiVirus:
The error indicates that BitDefender is crashing during the SAB install, but it is not clear why.
BitDefender has never been installed on this laptop. It’s my personal laptop.
The only AV ever installed is VIPRE, laptop is only a few months old.
Vipre seems to have file by that name as well.
https://www.advanceduninstaller.com/VIPRE-Antivirus-Plus-7d802213d77875893f1a9e1a61ffbc21-application.htm
It looks like VIPRE uses the BitDefender engine:
Checking the installed files, we found VIPRE using the Bitdefender engine as well as its own.
VIPRE Antivirus solutions review | TechRadar
Download a fresh copy to your system after deleting the current one you have. Run CCleaner and then install the new one you downloaded