Are you sure you're looking at https://www.php.net/manual/en/function.session-create-id.php?
Because,

> Warning: session_create_id(): Failed to create new ID in index.php on line 20.
> Generating new session id is not allowed when the session is already started.
The example is working for me.

> Also at line 16, the if statement need an integer because the output of session_status is an integer.
It does that already.

> Can the documentation for the "session-status" also be updated with the integer return values?
It does that too.

> The example also uses "session_commit()", this is an alias of "session_write_close", wouldn't it be
> better to use "session_write_close" instead of "session_commit" ?
The alias is not deprecated, but it probably would be better, yes.

For the first question: The sample code is working fine for me.

What version are you using?

Do you perhaps have session.auto_start enabled?

For the second question: PHP_SESSION_ACTIVE is an integer.

The def. environment is PHP 7.4.3 (xamp installation on Windows).
session.auto_start = "Off".
"display_errors" and "display_startup_errors" values are "On".
Here I get the warnings.

Tested example in prod. environment with PHP 7.3.17.
session.auto_start = "Off"
No warning because the most hosted platform has the "display_errors" and "display_startup_errors" at "Off" so the warnings and errors are suppressed. No output to webbrowser.

About the session-status.
echo session_status; gives int. as answer in the browser (values 0 or 1 or 2)
The explanation of the return values doesn't explain the link between these values 0, 1 & 2.
The contributed note from "sasi dot viragelet at gmail dot co" gives the answer.
Perhaps we can use that info to improve the documentation.

Just my 2 cents.
Have a nice day.

> Here I get the warnings.
Exactly what are they?

> The explanation of the return values doesn't explain the link between these values 0, 1 & 2.
Use the constants. If you want something you can read, use the constants to output human friendly strings like "active".

Exact warning: from def. environment:
Warning: session_create_id(): Failed to create new ID in E:\xampp\htdocs\8\index.php on line 20

The only way I see session_create_id failing is either (a) you don't have good enough crypto, or (b) you're using a custom session handler that's not behaving well.

So what are you session settings?

Session Support				enabled
Registered save handlers		files user
Registered serializer handlers		php_serialize php php_binary

Directive				Local Value		Master Value
session.auto_start			Off			Off
session.cache_expire			180			180
session.cache_limiter			nocache			nocache
session.cookie_domain			no value		no value
session.cookie_httponly			no value		no value
session.cookie_lifetime			0			0
session.cookie_path			/			/
session.cookie_samesite			no value		no value
session.cookie_secure			0			0
session.gc_divisor			1000			1000
session.gc_maxlifetime			1440			1440
session.gc_probability			1			1
session.lazy_write			On			On
session.name				PHPSESSID		PHPSESSID
session.referer_check			no value		no value
session.save_handler			files			files
session.save_path			E:\xampp\tmp		E:\xampp\tmp
session.serialize_handler		php			php
session.sid_bits_per_character		5			5
session.sid_length			26			26
session.upload_progress.cleanup		On			On
session.upload_progress.enabled		On			On
session.upload_progress.freq		1%			1%
session.upload_progress.min_freq	1			1
session.upload_progress.name		PHP_SESSION_UPLOAD_PROGRESS	PHP_SESSION_UPLOAD_PROGRESS
session.upload_progress.prefix		upload_progress_	upload_progress_
session.use_cookies			1			1
session.use_only_cookies		1			1	
session.use_strict_mode			0			0
session.use_trans_sid			0			0

I hope, this is the info you asked for.
Have a nice day.

The settings look fine, in that you're using the regular files handler.

But I find it hard to believe the crypto is the problem. Are you able to use random_bytes() without problems?

This is most likely a duplicate of bug #79413, which is fixed as
of PHP 7.3.17 and 7.4.5, respectively.

Yesterday evening I discovered that Example #1 was working correctly on an older version op XAMPP (PHP 7.2.9)(other pc)
Updated my current XAMPP with PHP 7.4.6.
Example works fine.

Thank you both for your time and support.