Skip to main content

This site requires you to update your browser. Your browsing experience maybe affected by not having the most up to date version.

Installing SilverStripe /

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

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

[User Error] Bad class to singleton() - PageKarriere


4 Posts   2852 Views


Community Member, 11 Posts

11 August 2010 at 12:33am

Hey guys,

I did a fresh install on a webserver that is not my own. Now I get the problem "[User Error] Bad class to singleton() - PageKarriere" when accessing the /admin panel (via silverstripe/index.php/admin because i do not have mod_rewrite on the server).
Note: PageKarriere is a page type i have customized for the website.

Now when i delete the custom page types and leave only the "" in /mysite/code, everything works fine. But as soon as i add one of the custom pages (which already work on another webserver and on my localhost), i get the bad class to singleton() error again.
Can anyone explain the function singleton() to me and maybe what the problem is?

On the forums i only found "not really" related topics, which all describe a different problem which cause the singleton() error.
Find the full error code below.

I know that this is probably a very easy problem, but i am just not seeing the solution ^^

Thanks in advance for all answers i get =)

Kindest Regards,

[User Error] Bad class to singleton() - PageKarriere
GET /silverstripe/index.php/admin

Line 334 in /www/

325 *
326 * @param string $className
327 * @return Object
328 */
329 function singleton($className) {
330    global $_SINGLETONS;
331    if(!isset($className)) user_error("singleton() Called without a class", E_USER_ERROR);
332    if(!is_string($className)) user_error("singleton() passed bad class_name: " . var_export($className,true), E_USER_ERROR);
333    if(!isset($_SINGLETONS[$className])) {
334     if(!class_exists($className)) user_error("Bad class to singleton() - $className", E_USER_ERROR);
335       $_SINGLETONS[$className] = Object::strong_create($className,null, true);
336       if(!$_SINGLETONS[$className]) user_error("singleton() Unknown class '$className'", E_USER_ERROR);
337    }
338    return $_SINGLETONS[$className];
339 }


* Bad class to singleton() - PageKarriere
Line 334 of Core.php
* singleton(PageKarriere)
Line 322 of SiteTree.php
* SiteTree::page_type_classes()
Line 341 of CMSMain.php
* CMSMain->PageTypes()
Line 1188 of CMSMain.php
* CMSMain->AddPageOptionsForm()
Line 369 of ViewableData.php
* ViewableData->obj(AddPageOptionsForm)
Line 45 of
* include(/www/
Line 420 of SSViewer.php
* SSViewer->process(CMSMain)
Line 342 of ViewableData.php
* ViewableData->renderWith(Array)
Line 481 of LeftAndMain.php
* LeftAndMain->Left()
Line 369 of ViewableData.php
* ViewableData->obj(Left,,,1)
Line 446 of ViewableData.php
* ViewableData->XML_val(Left,,1)
Line 59 of
* include(/www/
Line 420 of SSViewer.php
* SSViewer->process(CMSMain)
Line 202 of Controller.php
* Controller->handleAction(SS_HTTPRequest)
Line 137 of RequestHandler.php
* RequestHandler->handleRequest(SS_HTTPRequest)
Line 147 of Controller.php
* Controller->handleRequest(SS_HTTPRequest)
Line 281 of Director.php
* Director::handleRequest(SS_HTTPRequest,Session)
Line 124 of Director.php
* Director::direct(admin)
Line 127 of main.php
* require_once(/www/
Line 63 of index.php


Forum Moderator, 922 Posts

11 August 2010 at 11:17am

Edited: 11/08/2010 11:17am

If you add or remove a class you need to run ?flush=all in the URL for the class manifest to be reloaded.

If you're adding or removing a class which requires database tables or columns, it's best to run dev/build?flush=all so the database is rebuilt as well as the class manifest.



Community Member, 11 Posts

11 August 2010 at 8:50pm

Edited: 11/08/2010 8:57pm

Ah, i am sorry. I did not mention that. I did flush the database with /dev/build?flush=1 aswell as /dev/build?flush=all.
But as I did it again just now, to be sure, i now get another problem:

Website Error
There has been an error

The website server has not been able to respond to your request.

How do i get more information about the problem? (Developer Mode?)

When i delete the custom pages and flush the database mit /dev/build?flush=all, i do not get an error when accessing the silverstripe/index.php/admin panel. However the Panel does not load anymore. There is just the screen "Loading...Welcome to Silverstripe now Loading" (see attachement). I had this problem before the problem "bad class to singleton()" but simply because I entered "silverstripe/admin" instead of "silverstripe/index.php/admin". But now I am typing in the correct URL and i get the loading screen.


Attached Files

Community Member, 11 Posts

24 August 2010 at 2:39am


It's me again. Any chance of getting an answer to this?
I could really need the help and i still can't get it fixed.

Kindest Regards,