title: mongodb remove fails on "invalid object id"
body: <p>I'm trying to delete documents using MongoDB shell, but for some reason it keeps failing on "invalid object id: length"</p>
  
  <p><strong>query</strong>:</p>
  
  <pre><code>db.collections.remove( { _id : ObjectId("FF125DF6-E977-404A-9E8C-600CDAFEFF53" )} );
  </code></pre>
  
  <p><strong>error</strong>:</p>
  
  <blockquote>
    <p>Mon Dec 24 03:11:15 Assertion: 10448:invalid object id: length
    0x6073f1 0x5d1aa9 0x5ac3f1 0x5b84f4 0x6aa5ac 0x6aaec8 0x69e4e7
    0x6aa13f 0x668e46 0x668ec2 0x66a2ce 0x5cbcc4 0x4a44a6 0x4a67e6
    0x7f2554e2fcdd 0x49f669   mongo(_ZN5mongo15printStackTraceERSo+0x21)
    [0x6073f1]  mongo(_ZN5mongo11msgassertedEiPKc+0x99) [0x5d1aa9] 
    mongo() [0x5ac3f1] 
    mongo(_ZN5mongo21object_id_constructorEP9JSContextP8JSObjectjPlS4_+0x2b4)
    [0x5b84f4]  mongo(js_Invoke+0x40c) [0x6aa5ac] 
    mongo(js_InvokeConstructor+0x108) [0x6aaec8] 
    mongo(js_Interpret+0x37c7) [0x69e4e7]  mongo(js_Execute+0x36f)
    [0x6aa13f]  mongo(JS_EvaluateUCScriptForPrincipals+0x66) [0x668e46] 
    mongo(JS_EvaluateUCScript+0x22) [0x668ec2] 
    mongo(JS_EvaluateScript+0x6e) [0x66a2ce] 
    mongo(_ZN5mongo7SMScope4execERKNS_10StringDataERKSsbbbi+0x144)
    [0x5cbcc4]  mongo(_Z5_mainiPPc+0x2156) [0x4a44a6]  mongo(main+0x26)
    [0x4a67e6]  /lib64/libc.so.6(__libc_start_main+0xfd) [0x7f2554e2fcdd] 
    mongo(__gxx_personality_v0+0x2a1) [0x49f669] Mon Dec 24 03:11:15
    Error: invalid object id: length (shell):1</p>
  </blockquote>
  
  <p>I tried running </p>
  
  <pre><code>db.repairDatabase();
  </code></pre>
  
  <p>but nothing is changed.
  from checking around i see that its a known issue,is there a workaround for this?</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>here is the document as it is in the db:</p>
  
  <blockquote>
    <p>{</p>
    
    <p>"_id": "FF125DF6-E977-404A-9E8C-600CDAFEFF53",</p>
    
    <p>"data": {</p>
  
  <pre><code>   "files": [
     ],
  
     "categories": [
    ],
  
     "trash": [
     ]
   }
  </code></pre>
    
    <p>}</p>
  </blockquote>
  
  <p>Thanks!</p>