Calendar.setup error on CMS Edit Page

Hello!
Im having such an annoying problem that i cant solve.
Im the developer of a site almost finished (supposed to go live tomorrow) and an error began to appear today and I cant get whats going on.
The error is thrown, when I create 1 of my 4 types of items inside FlexiContent (the other ones doesnt have any error) is the following:

Calendar.setup:
Nothing to setup (no fields found). Please check your code
after that alert error 3 times, pages loades and crashed without loading any of the params, neither categories.
What is weird is that this isnt happening with ALL my items of that type, just the ones assigne to 2 or 3 categories. I have checked and compared those categories with the rest and they are ok.

But when I create an item to that type, and ANY category and put APPLY, when it tries to load all the other info, i get that message again.
has anybody seen this message?

Im really worried about this i have been 8 hours and couldnt solve it. Checked on the web but nothing to do still.
Thanks in advance!!

I have an error of JS seen in Firebug console that is:
$("params-" + element) is null
[Break on this error] }).chain(function(){

Still cant get this fixed
thanks!

hello what is your php version ?