Blender and blender@lts casks fail to download with HTTP 403 from download.blender.org

[jacobmoberly]

Verification

• I understand that if I ignore these instructions, my issue may be closed without review.
• I have retried my command with --force.
• I ran brew update-reset && brew update and retried my command.
• I ran brew doctor, fixed as many issues as possible and retried my command.
• I have checked the instructions for reporting bugs.
• I made doubly sure this is not a checksum does not match / SHA256 mismatch error (do not open an issue before trying to open a PR to fix first).

Description of issue

What were you trying to do?

Install the Blender cask.

brew install --cask blender

or

brew install --cask blender@lts

What happened?

Both casks fail with an HTTP 403.

Error: Download failed on Cask 'blender' with message:
Download failed: https://download.blender.org/release/Blender5.2/blender-5.2.0-macos-arm64.dmg
curl: (56) The requested URL returned error: 403

The LTS cask fails similarly:

Error: Download failed on Cask 'blender@lts' with message:
Download failed: https://download.blender.org/release/Blender4.5/blender-4.5.11-macos-arm64.dmg
curl: (56) The requested URL returned error: 403

Testing the URL directly:

curl -I https://download.blender.org/release/Blender5.2/blender-5.2.0-macos-arm64.dmg

returns:

HTTP/2 403
cf-mitigated: challenge
server: cloudflare

Requesting the release directory:

curl https://download.blender.org/release/Blender5.2/

returns Cloudflare's "Just a moment..." page instead of the directory listing.

What did you expect to happen?

The cask should download normally.

Command that failed

brew install --cask blender

Output of command with --verbose --debug

/opt/homebrew/Library/Homebrew/brew.rb (Cask::CaskLoader::FromAPILoader): loading blender
==> Would install 1 cask:
blender
==> Fetching downloads for: blender
/opt/homebrew/Library/Homebrew/brew.rb (Cask::CaskLoader::FromAPILoader): loading blender@lts
==> Verifying checksum for '854f926f46b66a4c972c38c387304c3739ea15d6cb836645f99afdaac8306e1f--blender.rb'
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 -V
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 -V
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 --fail --location --silent --head https://download.blender.org/release/Blender5.2/blender-5.2.0-macos-arm64.dmg
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 -V
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 --fail --location --silent --head --request GET --http1.1 https://download.blender.org/release/Blender5.2/blender-5.2.0-macos-arm64.dmg
✔︎ API Source blender.rb                                                                                                                                                                                                           Verified      2.7KB/  2.7KB
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 -V
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 -V
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 --fail --location --silent --head https://download.blender.org/release/Blender5.2/blender-5.2.0-macos-arm64.dmg
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 -V
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 --fail --location --silent --head --request GET --http1.1 https://download.blender.org/release/Blender5.2/blender-5.2.0-macos-arm64.dmg
/usr/bin/env /opt/homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --show-error --user-agent Homebrew/6.0.11-28-gf9e050f\ \(Macintosh\;\ arm64\ Mac\ OS\ X\ 26.5.2\)\ curl/8.7.1 --header Accept-Language:\ en --retry 3 -V
✘ Cask blender (5.2.0)
Error: Download failed on Cask 'blender' with message: Download failed: https://download.blender.org/release/Blender5.2/blender-5.2.0-macos-arm64.dmg
% Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0 61769    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
curl: (56) The requested URL returned error: 403
Error: Kernel.exit
/opt/homebrew/Library/Homebrew/cmd/install.rb:396:in 'Kernel#exit'
/opt/homebrew/Library/Homebrew/cmd/install.rb:396:in 'Homebrew::Cmd::InstallCmd#run'
/opt/homebrew/Library/Homebrew/brew.rb:121:in '<main>'

Output of brew doctor and brew config

Doctor:
Your system is ready to brew.

Config:
HOMEBREW_VERSION: 6.0.11-28-gf9e050f
ORIGIN: https://github.com/Homebrew/brew
HEAD: f9e050ff085346db38abdab99fac279aa08b6b93
Last commit: 2 hours ago
Branch: main
Core tap: N/A
Core cask tap: N/A
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DOWNLOAD_CONCURRENCY: 24
HOMEBREW_FORBID_PACKAGES_FROM_PATHS: set
HOMEBREW_MAKE_JOBS: 12
HOMEBREW_REQUIRE_TAP_TRUST: set
Homebrew Ruby: 4.0.6 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/4.0.6/bin/ruby
CPU: dodeca-core 64-bit arm_lobos
Clang: 21.0.0 build 2100
Git: 2.50.1 => /Library/Developer/CommandLineTools/usr/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 26.5.2-arm64
CLT: 26.5.0.0.1777544298
Xcode: N/A
Rosetta 2: false

Output of brew tap

teamookla/speedtest

[SSakutaro]

@jacobmoberly
Could you try again? I just ran brew install --cask blender@lts after running brew clenup -s, and Blender installed successfully.

░▒▓  ╱  ~ ▓▒░ brew install --cask blender@lts ░▒▓ ✔ ╱ 4s  ╱ 13:23:01  ▓▒░
✔︎ JSON API packages.arm64_tahoe.jws.json Downloaded 15.3MB/ 15.3MB
==> Would install 1 cask:
blender@lts
==> Fetching downloads for: blender@lts
✔︎ API Source blender@lts.rb Verified 1.4KB/ 1.4KB
✔︎ Cask blender@lts (4.5.11) Downloaded 308.3MB/308.3MB
==> Installing Cask blender@lts
==> Moving App 'Blender.app' to '/Applications/Blender.app'
==> Linking Binary 'blender.wrapper.sh' to '/opt/homebrew/bin/blender'
🍺 blender@lts was successfully installed!

░▒▓  ╱  ~ ▓▒░ curl -I https://download.blender.org/release/Blender5.2/blender-5.2.0-macos-arm64.dmg
HTTP/2 200
date: Thu, 16 Jul 2026 04:25:01 GMT
content-type: application/octet-stream
content-length: 346163615
server: cloudflare
last-modified: Tue, 14 Jul 2026 07:24:15 GMT
etag: "6a55e41f-14a2099f"
cache-control: public, max-age=2592000
x-content-type-options: nosniff
strict-transport-security: max-age=63072000; includeSubDomains; preload
accept-ranges: bytes
age: 161554
cf-cache-status: HIT
x-permitted-cross-domain-policies: none
cf-ray: a1be3d958fd6b92b-NRT

[jacobmoberly]

@SSakutaro
Hi thanks for the comment. I went ahead and ran brew cleanup -s and reran the brew install, but unfortunately I still get the same http 403 error on curl. From me looking into it, it seems that Blender is forcing downloads through cloudflare if the download is not coming from a browser.

I confirmed this because if I directly curl the download link, I still get the 403. But if I visit the link in a browser, I am able to download the .dmg just fine. So for whatever reason, when brew is trying to install it, it is failing that cloudflare check.

So I don't know if this is just a me problem, but if it is, I don't know why it is happening. All my other managed packages update and run just fine, but I noticed yesterday during my brew upgrade, blender was failing each time. So maybe they changed things when 5.2.0 came out, or maybe cloudflare is just not liking my IP. Happy to hear any other thoughts or recommendations.

[frogLiving]

I too ran the commands suggested above. I was unable to upgrade blender. I removed and attempted to reinstall same behavior.

Here is the behavior I observed from Cloudfare. Its attempting to do some sort of client verification. Once it does that it begins the download. I am able to copy the link from brew and download the application but I am not able to use brew to obtain it. The following screen shot is from zen browser when using the url brew provides. There appears to be a handshake before the download request is returned to blender.org

I was able to capture the challenge prompt.

[CmptrExpr]

I am seeing the same problem, but from an upgrade (brew upgrade blender). From a browser, I enter the failed download URL and get a page for "human verification." So, evidently, the blender team changed their website to require this validation step prior to actually getting to the download file link. This is what is causing the 403 error.

Fixing this requires action on the Blender site to accept the download request without the human verification step. The alternative would be to add code to brew to be able to check the box appropriate but this would not be a generic fix. A better solution would be to add agent authentication to the site, again requiring a change to the Blender download site.

[roncli]

This is also happening from Winget.