What would cause an Internal Server Error on saving entry When I try to save a new entry as a child under a Structure entry, I get the following error:


  Internal Server Error
  
  Object of class Craft\ElementCriteriaModel could not be converted to
  string


I also get the same error when I tried to move it out to it's own Channel instead, so I am not sure what could be causing it.

I have several fields in this entry, most notably the cause would be an Entries field and Tags field. Both seem to select the correct values fine.
I have solved the problem myself while debugging.

I had the Entry Type "Title" field set to {relatedFieldName} Post which was causing the error. When I changed it to a plain string or other non-object field name, it no longer errors out.

I was unclear about how the Title field works exactly.