Premiere Pro 26.5.2 won't install or update on Windows (error 127, "Failed to allocate buffer" for Adobe Premiere Pro.exe), but 26.5.1 installs fine

Summary
Premiere Pro 26.5.2.5 always fails to install with error 127 during the extract step, whether as a fresh install or as an update from 26.5.1. Premiere Pro 26.5.1.1 installs on the first try on the same machine, a few minutes later, with nothing changed in between. The two versions' Adobe Premiere Pro.exe are the same size (780,952,072 bytes), so the size of the file alone doesn't explain it. Something about how the 26.5.2 package is unpacked must be different.

This looks like the same bug as "Cannot update Beta" and "can't install premiere pro beta", but now in a regular (non-beta) release.

System

• Windows 11 Pro for Workstations, build 26200
• Intel Xeon Gold 6136, 46.7 GB RAM, NVIDIA GeForce GTX 1080 Ti
• Creative Cloud desktop 6.10.0.253 (installer Setup.exe 6.10.0.252)
• 700+ GB free on C:

Log (C:\Program Files (x86)\Common Files\Adobe\Installers\Install.log), repeated for every extract attempt:

ERROR: Path:C:\adobeTemp already exists

ERROR: Failed to allocate buffer for file C:\adobeTemp\ETR2CE9.tmp\1\universal\App\Adobe Premiere Pro.exe of size 780952072

ERROR: Failed memory allocation after sleep also

ERROR: Extraction failed for file C:\adobeTemp\ETR2CE9.tmp\1\universal\App\Adobe Premiere Pro.exe with returnCode=-1

FATAL: Error occurred in extract of package (Name: AdobePremierePro26AllTrial Version: 26.5.2.5). Error code: '127'

What I've tried (none of it fixed 26.5.2):

• Changed the page file from a fixed 400 MB–4 GB to system-managed, then rebooted
• Rebooted several times
• Retried more than 6 times over two days, both as a fresh install and as an update from 26.5.1

What works: installing 26.5.1.1 through Other versions. It unpacks and installs successfully (exit code 0).

Probable cause: The installer (HDBox\Setup.exe) is a 32-bit program that isn't large-address-aware, so it can only use 2 GB of memory. For 26.5.2 it seems to try loading the whole 780 MB file into memory at once, and it can't get a single block that large within its 2 GB. 26.5.1's identical-size file unpacks fine, so the 26.5.2 package (or the way the installer handles it) is the likely culprit.

I can send the full Install.log if that would help.