While implementing a recommendation from Mehdi that is related to another issue, I have encountered this problem. I am converting a Content Type from object type Free to object type Article. The Content Type form has many fields-- 171 to be exact. However, while recreating the content type, I am unable to add more fields from the form Construction (Site Form view).

When I click the Add Field (+) link, the Add Field form opens correctly, but when I try to save the form contents, it will not save. The animation appears to indicate that it is processing, but the window never closes and the field is not saved. The only button that works is the Close button.

I can add already existing fields to the Content Type form and save it without any difficulty. But I'm unable to create new fields using the Add Field link.

I can also create new fields in the Field Manager, however I want to create fields that are linked to a single Content Type. Without the ability to add fields in form construction, I'm unable to do this.

Have I encountered some limit of the number of fields that an Article object can have? When using the Free object type previously, I was able to create the Content Type with all 171 fields without difficulty.