Bitrix Uploads

Bitrix upload errors can come from several layers: browser, nginx, PHP-FPM, Bitrix settings, or the application form itself.

This guide is for the common case where small files upload but larger files fail before Bitrix receives the request.

Typical Symptom

In Bitrix UI:

Network error

In HTTP response:

HTTP 413 Request Entity Too Large

If small files upload successfully but files around 5-16 MB fail with 413, the request is usually blocked by nginx before it reaches PHP or Bitrix.

Expected Bitrix Profile Limits

The Bitrix profile expects nginx server block to include:

client_max_body_size 64m;

The Bitrix PHP baseline expects PHP-FPM limits such as:

post_max_size = 64M
upload_max_filesize = 64M

Both layers matter. If nginx limit is smaller, PHP settings do not help because the request never reaches PHP.

What To Check First

Menu:

Applications -> Bitrix -> Bitrix status
Diagnostics -> Site health check

CLI:

sudo /root/simai-env/simai-admin.sh bitrix status --domain <domain>
sudo /root/simai-env/simai-admin.sh site doctor --domain <domain>

Expected checks:

Bitrix upload body limit: client_max_body_size 64m

If this is missing or failed, the active nginx config is not matching the Bitrix profile baseline.

Check Active Nginx Config

sudo grep -n "client_max_body_size" /etc/nginx/sites-enabled/<domain>.conf
sudo grep -n "urlrewrite.php" /etc/nginx/sites-enabled/<domain>.conf

Expected:

client_max_body_size 64m;
try_files $uri $uri/ /bitrix/urlrewrite.php?$args;

Check PHP-FPM Limits

Use site doctor first. If deeper inspection is needed, inspect the site PHP-FPM pool shown by:

sudo /root/simai-env/simai-admin.sh site info --domain <domain>

Look for:

post_max_size
upload_max_filesize

For common Bitrix FileInput uploads, both should be at least as large as the intended upload size.

Why Bitrix Shows Network Error

When nginx returns 413, Bitrix JavaScript may only show a generic upload/network failure. The application form did not necessarily reject the file; nginx rejected the request body before /bitrix/tools/upload.php or another Bitrix upload endpoint could process it.

Common Causes

• active nginx config lost client_max_body_size 64m
• SSL or manual nginx edit regenerated a generic server block instead of preserving Bitrix template
• old migrated site config predates the current Bitrix profile template
• PHP limits are lower than the Bitrix field/interface limit
• Bitrix field setting has its own lower limit

Repair Direction

If nginx limit is missing, restore the Bitrix nginx baseline:

client_max_body_size 64m;

After nginx config change:

sudo nginx -t
sudo systemctl reload nginx
sudo /root/simai-env/simai-admin.sh site doctor --domain <domain>

If PHP-FPM limits are wrong, reapply Bitrix baseline:

sudo /root/simai-env/simai-admin.sh bitrix php-baseline-sync --domain <domain>
sudo /root/simai-env/simai-admin.sh site doctor --domain <domain>

Test After Repair

Use the same user-facing form that failed, and test with at least two files:

• small file below 1 MB
• larger file above the previous failure threshold

If the HTTP response is no longer 413 but Bitrix still rejects the file, inspect Bitrix field/module settings next.

Handoff Checklist

Before saying upload limits are fixed:

• small upload succeeds
• previously failing larger upload no longer returns 413
• bitrix status shows upload body limit ready
• site doctor has no Bitrix nginx upload failure
• PHP-FPM post_max_size and upload_max_filesize match the intended limit
• Bitrix field/module upload limit is not lower than the test file size