New Post: Unexpected error submitting a new/edit form when using SPCascadeDropdowns and not setting a required field

Situation:

• Using a straigtforward Cascading dropdown with a parent and child column in new/editform.
  

Used:

• Office 365 (SP 2013): Dutch language
• Event (Calendar) list.
• Content Type based on "Event" CT.
• Parent column A: single value lookup to custom list.
• Child column B: single value lookup to custom lookup list.
• jquery 1.10.2
• spservices 2014-1
  

Circumstances:

• Both column A and B are required
• Not using the promptext() or nonetext()
• Default value of column A is the first value in the list
• Default value column B is (none)
• The cascading works
  

Problem:

• When submitting the form without setting the B column(required) I get an unexpected error. Probably because of the (none) value.
• The odd thing is: I have another list (custom list, not event list) with the same setup. Also even when using nonetext(), SharePoint appoints that it's a required column and must be set.
• So I'm wondering what's going on.
  

the code I'm using is:

//Cascade cliënt-doelstelling
$().SPServices.SPCascadeDropdowns({
  relationshipList: "Zorgleefplan doelstellingen",
  relationshipListParentColumn: "Cli_x00eb_nt",
  relationshipListChildColumn: "Title",
  parentColumn: "A Vereist veld",
  childColumn: "B Vereist veld",
  simpleChild: true,    
  matchOnId: true,
  debug: false
});

*note: the "Vereist veld" is needed whenever I set the column to required since 2014-1 does not solve that problem (at least not for me :-) )

Thanks in advance. SPServices is a great piece of work!