Update:

I have monitored what happens here in firebug. Attempting to add any of the following field types (and only these field types) to a form in the CMS:

1. Dropdown
2. Radio Button
3. Checkbox

Result in only a <br /> being inserted onto the form instead of the actual form element.

Video of the problem here:
http://www.screencast.com/users/Zanzo/folders/Jing/media/a67a5713-b89e-4c88-a79a-ed4e5b22598d

To reiterate - I was having the same problem as the title of this thread after upgrading from 2.2.3 to 2.3.1 + userforms 0.1.0.

The steps I took to this point were:
1. Delete sapphire, cms and jsparty from webroot.
2. Copy replacement folders for these three, plus userforms direcory to webroot
3. Run /dev/build/?flush=1 on the site
4. Contact form has the error as specified in the subject of this thread
5. Go to CMS, delete any Dropdowns from the orignal form
6. Attempt to add new Dropdown to the page using the CMS.

Any further help to fix this? I have tested a fresh install of 2.3.1 with userforms 0.1.0 and all seems fine. The only other real different is the database.

Cheers
Aaron

Another update.

I used firebug to watch the event when I click on "dropdown":

It calls up "http://vivaexp.localhost/admin/EditForm/field/Fields/addfield?NewID=NaN&Type=Dropdown". Sometimes the "NaN" is "undefined".

Here is the response everytime anyway:

<b>Fatal error</b>: Class 'EditableMultipleOptionField' not found in <b>C:\wamp\www\viva_exp_2.3\sapphire
\core\model\DataObject.php(1417) : eval()'d code</b> on line <b>1</b>

The exact same error occurs when I click on "checkbox" or "radio"

Are you using the latest and greatest trunk? EditableMultipleOptionField is a new addition but should have been in the packages for the last week or so. Try update and run /dev/build/

Hi Willr, this is 2.3.1 stable. Are you saying that we need the latest trunk to run userforms 0.1.0?

No by the sounds of it you are not running 0.1 you are running a newer version of userforms See whats included in 0.1 here - http://open/browser/modules/userforms/tags/0.1.0. EditableMultipleOptionField and any calls to it should not be related to 0.1 and all self contained in the trunk version of the code. What file in 0.1 is calling EditableMultipleOptionField?

No by the sounds of it you are not running 0.1 you are running a newer version of userforms 

I only have one version of userforms now, downloaded from the modules own download page.

See whats included in 0.1 here - http://open/browser/modules/userforms/tags/0.1.0. 

What is that URL?

EditableMultipleOptionField and any calls to it should not be related to 0.1 and all self contained in the trunk version of the code. What file in 0.1 is calling EditableMultipleOptionField?

http://www.domain.com/jsparty/prototype.js?m=1226464322

Nothing more on this?

I am now having to give my boss reasons why we shouldn't be investigating another CMS of choice just yet. I kind of understand where he's coming from. He's just paid me two days to get a 5 field contact page working, and I'm about to clock a third by the looks.

This is starting to look more and more like an utter disaster, with a dozen Silverstripe sites and not a single one of them can be updated. Forever trapped as version 2.2.1 to 2.2.3.

What is that URL?...

That URL was the 0.1 release, I think if your error related to EditableMultiFieldOption it is not running on 0.1 - are you sure its not a daily build release? Could you post a screenshot of your admin interface with the form (or lack of one) ? You could have got a bastard child of 0.1 and the next release.