title: Saving ODB File by Python: error attempt to truncate read only table
body: <p>I want to read ODB file and then add a field, and save the resulting ODB file.
  The coode is very easy (given below).
  But I get the error message:
  OdbError: database save failed. **error attempt to truncate read only table.</p>
  
  <p>Probably, the problem is in the ODB file, not in code itself.</p>
  
  <p>Has anyone an idea what can be wrong there?</p>
  
  <p>The code is:</p>
  
  <pre><code>from odbAccess import *
  from abaqusConstants import *
  from odbMaterial import *
  from odbSection import *
  from numpy import fabs as fabs
  import numpy as np
  import sys
  import math
  import os
  import datetime
  from types import IntType
  print('       Reading ODB    ' ) 
  odb = openOdb(path='iog.odb') 
  odb.save()
  odb.close()
  </code></pre>