The login to the WP-site does not function any more

[saint_malo]

good day dear community,

The login to the WP-site does not function any more - i have changed the passwd in the backend - but as for now the login does not work any more.
could it be that i have to

_ try out to switch off all the plugins (one by one)
_ try to look for the cache of the browser or the server
_ thry to set the themes_ back the site is runnig on

btw_: atm i do not have access to the backend of the DB - but if i have such - i will have a closer look at the tables

is ther any thing i could do more here - and now !?`

look forward to hear from you

 

[hipcat]

Do you mean user logins for everyone, or just the admin login for you? Might be a caching issue...

 

[saint_malo]

hi there -good day dear hipcat
thank you for the reply.
will try out this - possibility. i will check it.

come back and report later the weekend.
have a great day.
greetings.

 

[lionelwatson]

might be a crush caused by newly installed plug-in if the log-in site showed 501 errors. You can change filename of 'plug-in' in cpanel-file manager-public-wp content into 'plug-in temp' and test again. If then you can log-in, you may need to check one by one see which is the exact plug-in caused the error and had it removed.

 

[saint_malo]

good day dear Lionelwatson - thank you for the reply

might be a crush caused by newly installed plug-in if the log-in site showed 501 errors.

good idea - i will try out this!

You can change filename of 'plug-in' in cpanel-file manager-public-wp content into 'plug-in temp' and test again. If then you can log-in, you may need to check one by one see which is the exact plug-in caused the error and had it removed.

this is a very good idea! Thank you so much!

i definitly will try out this.

Greetings

 

[fabwebstudio]

It sounds like a common WordPress login issue that can happen due to plugin conflicts, caching, or database-related errors. Since you don’t currently have DB access, here are a few steps you can try right now:

Disable plugins manually:
Access your site via FTP or File Manager, go to wp-content/plugins, and rename the folder (e.g., plugins_old). This will deactivate all plugins and help you check if one of them caused the issue.

Clear browser and server cache:
Sometimes caching plugins or CDN (like Cloudflare) can store old login sessions. Clear all caches and try again.

Switch to a default theme:
If possible, rename your active theme folder under wp-content/themes — WordPress will fall back to a default theme like Twenty Twenty-Four.

Check .htaccess file:
Rename it temporarily to see if corrupted rewrite rules are blocking login.

Once you regain DB access, you can also reset the password directly in the wp_users table or verify the siteurl and home values in wp_options.

If none of these work, try enabling debug mode in wp-config.php (define('WP_DEBUG', true) to identify PHP or plugin errors causing the login failure.

 

[saint_malo]

thank you so much for the reply dear


i erased all the stuff
wp-admin and wp-includes !


with a fresh code from wordpress.org

wp-content und wp-config.php stay as is now!!!

i have the debug mode - activated -- i need more information now!!


argh - i have to check the basics o the server.


many many greetings
matze )

 

[saint_malo]

good day dear fabwebstudio

many thanks for the reply - glad to hear from you.

If none of these work, try enabling debug mode in wp-config.php (define('WP_DEBUG', true) to identify PHP or plugin errors causing the login failure.

this is very helpful:

argh - i have had a closer look at the debug log

believe it or not - i guess that i have some issues - that might be very big..

PHP Fatal error: Uncaught ValueError: Unable to generate salt

i did alot in the past few days - to find out why the login crashes all the time:

my findings:

WordPress core is fresh. Database is running. Login fails because PHP's `password_hash()` cannot generate a salt.
The PHP build is likely missing the `crypt`, `bcrypt`, and `openssl` modules, or `password_hash()` is broken. so i am at the point to check all my PHP modules that are installed and activce or to recompile the whole PHP-thing."

More specifically:

`php -m` should list `openssl` and `password`.

`phpinfo()` shows whether bcrypt is supported.

Values: `CRYPT_BLOWFISH = 1` → must be present.

The problem is indeed on the server and explains exactly why my WordPress installation crashes during login.


my phpinfo shows (and why WordPress login crashes)

here i have had a quite IMPORTANT FINDING:

The `configure` line contains:

'--without-curl'

hmm - his means: **PHP was compiled without `cURL`**.

but - afaik WordPress uses `cURL` at several points in the login process – especially for password hashing/salting via `password_hash` when bcrypt or Argon2 is active.

Without `cURL` + missing system-wide entropy → PHP sometimes **cannot generate a salt**.

conclusion: This could be the explanation ( probably a exactly one) what causes the error "Unable to generate salt" – at least the text perfectly matches this setup.

Well - i need to have a closer look at the php - and to have make sure that i have the php compiled with all the above mentioned stuff.


i just want to share these thoughts with you here.

greetings

 

[Marc van Leeuwen]

Try these first:

Clear cache - Browser cache, server cache (if using caching plugin)
Disable plugins - Use SFTP/File Manager to rename /wp-content/plugins folder temporarily, then rename back one plugin at a time
Switch to default theme - Rename your current theme folder via SFTP
Check wp-config.php - Verify database credentials are correct

If nothing works:

Check error logs (wp-content/debug.log)
Verify password was saved correctly in backend
Try resetting password via phpMyAdmin if you get database access

What error message do you see when trying to login?

 

[saint_malo]

good day dear Marc, glad to hear from you.

thank you for the hints:

still stuggling.

The login problem is still not resolved. We have confirmed that the login failure is caused by:

PHP Warning: password_hash(): Unable to generate salt
Resulting in "$wp" being stored in wp_users.user_pass

We performed the entropy test in a standalone PHP script:

var_dump(is_readable("/dev/urandom")); // bool(true)
var_dump(password_hash("test", PASSWORD_BCRYPT)); // Exception: Unable to generate salt
phpinfo();

So /dev/urandom is readable and accessible – but password_hash() still fails.
This means the problem is NOT a missing entropy source. `/dev/urandom` returns TRUE.

PHP versions tested:

PHP 8.3.27 (compiled with --with-password-argon2)
→ compiles successfully, but password_hash() always throws "Unable to generate salt"
→ wp_users table receives "$wp", login impossible

PHP 8.4.x (compiled with --with-openssl-argon2)
→ fails to compile at all unless OpenSSL ≥ 3.4
→ currently broken on our server

So we have a situation where:
• PHP 8.3 compiles, but Argon2 or bcrypt salt generation fails
• PHP 8.4 would require OpenSSL 3.4+, but PHP won’t compile successfully with it

The hosting admin believes this is a PHP/OpenSSL incompatibility.
We suspect that compiling PHP with Argon2 support requires a specific OpenSSL + libsodium combination, or a known patch.

My questions to the community:

1. Is there a known working compile configuration for PHP 8.3.x + WordPress 6.7/6.8 where password_hash() works with BCRYPT/Argon2?
2. Which exact compile flags are required?
(e.g. --with-password-argon2, --with-openssl, --with-libsodium, --with-mcrypt, etc.)
3. Is there a confirmed bug in PHP 8.3 regarding Argon2/BCRYPT and OpenSSL combinations?
4. Would downgrading to PHP 8.2 be recommended, and is there a known “safe” compile configuration for it?

i look forward to hear from you again..

greetings

ps. loong long live WordPress- i am sure that wordpress is not the problem here. I am pretty sure that the root-cause is in the server-config!
greetings