When editing a class definition on a site running in a master / slave environment eZ only returns a certain amount (or types) of attributes. There seems to be mostly images and relation attributes which do not show up. I have verified that this happens in the actual fetch, and not the template that displays them.

If I do a normal browser refresh while on the edit page of the class page I get the expected result, i.e. all the attributes show up.

If I try setting

UseSlaveServer=disabled

I get all the attributes as expected, and everything works.

It's also worth mentioning that if I disable

[OverrideSettings] Cache=disabled

it works with

UseSlaveServer=enabled

Steps to reproduce

1. Have a site using a master/slave setup with Cache settings enabled (i.e. as close to a live environment as possible.)
2. Edit a class definition that has image and relation attributes
3. See that there are missing attributes in the form
4. Refresh the page
5. See that all attribute show up as expected