Answers.Body: <p>I have solved the problem myself while debugging.</p>
  
  <p>I had the Entry Type "Title" field set to <code>{relatedFieldName} Post</code> which was causing the error. When I changed it to a plain string or other non-object field name, it no longer errors out.</p>
  
  <p>I was unclear about how the Title field works exactly.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-08-12T01:25:47.540Z
Answers.Text: Ah, very interesting! I actually stumbled across this today in a conversation with Ben Parizek... Any "related field" values are actually handled as ElementCriteriaModels, whereas most other fields would be handled as strings or JSON arrays. That totally explains why the error message complained about converting an **object** to a string. Thanks for reporting back!
Answers.UserDisplayName: Lindsey D
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-08-12T01:14:17.060Z
Answers.LastActivityDate: 2014-08-12T01:14:17.060Z
Answers.UserDisplayName: cmfolio
Body: <p>When I try to save a new entry as a child under a Structure entry, I get the following error:</p>
  
  <blockquote>
    <p><strong>Internal Server Error</strong></p>
    
    <p>Object of class Craft\ElementCriteriaModel could not be converted to
    string</p>
  </blockquote>
  
  <p>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.</p>
  
  <p>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.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2014-08-12T01:04:23.833Z
Comments.Text: Are you using a custom plugin? Or any plugins, for that matter? That's not an error that should crop up during normal CP usage.
Comments.UserDisplayName: Lindsey D
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2014-08-12T01:14:50.490Z
Comments.Text: I realized it was a random problem and posted my solution. Thanks for the help @LindseyD.
Comments.UserDisplayName: cmfolio
Tags: <entries><structure><error-message><channels>
Title: What would cause an Internal Server Error on saving entry
ThreadText: # What would cause an Internal Server Error on saving entry
  
  (Asked by: username_0 on 2014-08-12)
  
  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.
  
  **Tags:** entries, structure, error-message, channels
  
  > **Comments:**
  > **username_1**: Are you using a custom plugin? Or any plugins, for that matter? That's not an error that should crop up during normal CP usage.  
  > **username_0**: I realized it was a random problem and posted my solution. Thanks for the help @username_1.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_0 on 2014-08-12. Score: 1 | Accepted answer
  
  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.
  
  > **Comments:**
  > **username_1**: Ah, very interesting! I actually stumbled across this today in a conversation with Ben Parizek... Any "related field" values are actually handled as ElementCriteriaModels, whereas most other fields would be handled as strings or JSON arrays. That totally explains why the error message complained about converting an **object** to a string. Thanks for reporting back!  
  
  ---
  
  