Save and Update issue

Hi,
We are 50% done.
The issue is fixed in Joomla 4 but not in Joomla 5.
 

You're getting the same exact error in Joomla 5? Please be sure your Joomla 5 install is completely up to date and provide the full callstack for the error. The fix is compatible with Joomla 4 and 5.

Everything is fully updated.
1. Joomla 5 backend → Components → Community Builder → Edit a user profile
2. Make any change → click Save
3. Result: Redirected to the Administrator Home dashboard
4. I remain logged in (admin session intact), but the CB user changes are not saved

Observed behavior
No visible error message
No errors in browser console
Joomla debug + maximum error reporting enabled

Troubleshooting done so far
ACL: Checked, nothing suspicious found (logged in as Super User)
CB plugins: Disabled every non-core CB plugin → issue persists
Joomla plugins: Disabled all extensions/plugins globally → issue persists

Frontend Debug Info:
Joomla: 5.3.3
PHP: 8.2.29
Template: shaper_helixultimate
DB: MariaDB 10.6.19 (collation utf8mb3_general_ci / conn collation utf8mb4_general_ci)
Log warning: assets - No asset found for com_comprofiler.plugin.packagebuilder, falling back to com_comprofiler

Backend Debug Info:
When editing a user profile:
webauthn.system - Injecting WebAuthn Passwordless Login fields in user profile edit page

Question
Could this issue be related to the “Smart Search” handling you mentioned earlier?

Question
Could this issue be related to the “Smart Search” handling you mentioned earlier?

No, you've something else going on.

How many fields do you have? You might be hitting input limits and need to increase them in your servers PHP ini file.

I think not the case... I have 366 fields

Upload Max Filesize 16M
Post Max Size 16M
Memory Limit 128M
Open basedir /var/www/vhosts/mywebsitehere/:/tmp/
Display Errors On
Short Open Tags Off
File Uploads On
Output Buffering On
Session Save Path /var/lib/php/session
Session Auto Start 0
XML Enabled Yes
Zlib Enabled Yes
Native ZIP Enabled Yes
Disabled Functions opcache_get_status
Fileinfo Available Yes
Multibyte String (mbstring) Enabled Yes
GD Available Yes
iconv Available Yes
intl Available Yes
Maximum Input Variables 20000

Try unpublishing all tabs containing fields except for the core fields necessary to register a user (username, password, email) and try saving a test user (don't do this on a regular user as may result in data loss). This will let us know if it's a problem with a field. Something could be breaking the forms HTML for example.