Getting "Internal Server Error: Function 'dump' does not exist" when accessing/creating custom fields On my in-development version of a site I'm working on, I'm unable to access any of my custom fields without Craft displaying an error that reads:


  Internal Server Error Function "dump" does not exist


I can navigate to Settings > Fields but when I attempt to click on any of my fields to check/adjust settings or when I try to create a new field, I get the error screen. I'm able to access all other parts of the CP, create entries, adjust settings, etc.

The odd thing is that I have a working instance of the site running in my local environment. As part of my troubleshooting process, I dumped the database on the staging site and imported my local version. I also replaced the "craft" folder on my staging site with the one from my local site. The problem still persists.

I recently updated to the latest build (2.1.2569) so I first thought something in the update might need fixing, but my local instance is updated as well and completely functional.

In case it helps, I'm hosting my staging site on Arcustech and have had no issues up to now.

Any ideas what might be going wrong?
Adding as an answer because it was confirmed via a support ticket that a plugin was at fault.

Twig's dump method is only available in Craft when devMode is enabled. 

Turn it off, reproduce the problem, then search your craft/storage/runtime/logs files for [error].

The stack trace listed in that error log will show which plugin is causing the issue.

Chances are that plugin is calling Twig's dump somewhere in a template, assuming it will always be available, when that is not the case.