Strange issue after update to 2.10

[punkstjimmy]

Hi,

i'm having problems with the Contao backend after upgrading to 2.10.3 from 2.7.5.

It seems to occur whenever Contao makes an AJAX call. For example when click "Add an image" when editing a news article, instead of loading the sub palette I get an error. Also when I try to expand the Page Tree when viewing the site structure instead of opening the tree I get an error.

I get the following error message:
SyntaxError: JSON.parse: unexpected character

In firebug I can see that the response is showing a PHP error:
Fatal error: Call to a member function executePostActions() on a non-object in /home/server/abcd.co.uk/system/modules/backend/Backend.php on line 216

Any ideas what might be causing this, or where I should be looking to find out?

Cheers

[Moogi]

These sort of things are hard to diagnose without having access to the site and server themselves, but you should certainly try emptying out browser cache, emptying out Contao cache (tmp, html, scripts directories), and then double checking that the php script mentioned in the error is the same as the one in the current release (ie. it updated correctly).

I've had similar problems with the ajax functions on upgrades myself in the past and they went away after performing the above.

Cheers,
Moogi

[punkstjimmy]

Thanks for the reply!

It turns out we had an old extension installed that was rewriting the URL in the backend which only became a problem after upgrading to 2.10.