Panel error: mbstring extension

I am hoping someone can help me with an error I am having with the panel. When I go to the panel on my website (, I get this error:

Panel Error:
The mbstring extension must be installed

The hosting provider insists that mbstring is active and installed. This is the latest message they have sent me:

“The errors you are seeing are related to php_mbstring.dll which is a component of a windows server and will not work on our Linux servers .mbstring is definitely enabled on the server, the issue appears to lie in your script itself”

They have told me that they are running Apache 2.2 with Mod_Rewrite and should be able to satisfy the requirements to run Kirby.

The rest of the website functions perfectly. Can this really be the case?

The way Kirby detects that the extension is missing is by checking if there is a function named mb_split, which is one of the functions mbstring provides.

Could you please create a PHP file with the following content and check if there is mbstring somewhere on the resulting page:



If there isn’t, please send them the link to the phpinfo page and tell them that the extension is not enabled.

Thanks for your reply. Yes – the function appears to be there:

Hm, then I don’t know why it isn’t available in your Kirby installation. Could you please reply to the support what I wrote above (how Kirby detects it) and that it doesn’t relate at all to the Windows DLL?

Yes, I have emailed them and I will post their response when I receive it. Thanks again for your help.

Yes mb_split was the key. Panel works perfectly now – thanks very much for your help!

So that means, mb_split was missing although mbstring was enabled?

I believe that was the case. They didn’t tell me exactly what they did to fix the problem, but after I mentioned mb_split and asked whether they could activate or fix it, they sent an email back saying the problem had been fixed, and the panel works perfectly.

Ok, thanks, I added this to the troubleshooting docs for future reference.

Hi. I am having this problem too. My host says mbstring is enabled but wasn’t too sure about what role mb_split had to play. Via cpanel I have some options to change my php.ini file. There are 8 entries for mbstring but none mention mb_split. So currently can’t access /panel/. Any ideas?

If it is not disabled in the php.ini file, you need to ask your hoster to enable mb_split (or if they can’t or don’t want to do it, change your hosting provider).

Thanks @texnixe. Sorted now per your instructions

I think I might have got the same problem…

If i try to log in the panel I get a “HTTP ERROR 500”. It all worked fine for years.

running kirby v2
php info: PHP 8.0.16 - phpinfo()

Am i right?
If so, what would be the question I should send the host to explain the problem properly?

thx for any help!

You are using Kirby 2, which is not compatible with PHP 8, max supported PHP version is 7.4.

Note that Kirby 2 reached EOL at the end of 2020.

thx for the response.
So I cant get the panel to work with PHP 8 anymore?
(i dont have the skills or resources to upgrade to kirby 3)

If I were you, I’d downgrade to PHP 7.4 and update to the latest Kirby 2 version (if you are running an older version). And in the long run, update to Kirby 3 if possible. If you can’t handle it yourself, then it shouldn’t be difficult to find someone who can do it for you. If the site is not very complex, it shouldn’t be such a big effort.

thx for your response.
Where can i download the latest kirby2 release? doesnt seem to work anymore.

(following the guide: Kirby Updates | Kirby)

I am running kirby 2.5.12, downgraded server to PHP7.4 but still getting an internal server “HTTP ERROR 500” after panel login.

Any idea what I could do to trouble shoot?