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Installing SilverStripe /

Getting SilverStripe up and running on your computer and on your web server.

Moderators: martimiz, Sean, Ed, biapar, Willr, Ingo, swaiba

install SS3 gives undefined function mb_http_output()

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8 Posts   9512 Views

Bruce B

Community Member, 164 Posts

14 July 2012 at 8:29pm

I have installed SS3 successfully a couple of times on my local machine but my VPS doesn't want to know about it. It gives an error:

Fatal error: Call to undefined function mb_http_output() in /home/bbowden/public_html/framework/core/Core.php on line 206

This server holds already multiple instances of SS2.4. A quick code check shows that SS2.4 checked for the existence of mb_http_output before calling it while SS3 assumes it exists.

Looks like I need to work out how to install this module on my server or edit my SS3 core.php file. I don't like the second option but then again I have no idea how to attack the first. Google, here I come! (and I hope I don't break my server.)

Bruce B

Community Member, 164 Posts

14 July 2012 at 11:30pm

Looks like SS3 also requires MySQLi which was optional under SS2.4.

Discovered Easy Apache which makes compiling and installing new versions of PHP relatively pain-free.

SS3 is now running successfully.


Community Member, 6 Posts

2 December 2012 at 2:58pm

Helpful reply in that it helped me work with EasyApache but after trying this fix, updating the code to the latest release all it seems to have done is move the error line to 232.

Fatal error: Call to undefined function mb_http_output() in /home/spijker/public_html/ss/framework/core/Core.php on line 232

Any suggestions?



Forum Moderator, 922 Posts

5 December 2012 at 10:44am

Hi there,

SilverStripe requires the mbstring PHP extension is installed. Could you confirm you've got that installed?



Community Member, 8 Posts

2 February 2015 at 5:36pm

Still getting Fatal error: Call to undefined function mb_http_output() in in all my SS installs on my VPS on my local Windows dev machine using a WAMPSERVER environment.

MySQLi is running and so is mbstring.

These are the two issues I am aware of but still they do not work.

Any suggestions?


Community Member, 3 Posts

20 June 2017 at 9:34am

Just in-case anyone finds this issue on Google, I fixed my issue with this on Ubuntu 16 and PHP7.0 with the following:

sudo apt-get install php7.0-mbstring

If you have installed this already, or you just installed it make sure to enable it:

phpenmod mbstring

followed by:

apachectl graceful

Good luck!


Community Member, 3 Posts

24 June 2017 at 9:07am

@ryanpotternz Are you running SS3 or 4 on php 7?


Community Member, 3 Posts

29 June 2017 at 5:34am

@TheBnl it was/is 3.6.1