Error previewing an edited draft letter containing an ordered list

While previewing a letter draft with an ordered list, you encounter the following error:

Solution

1. Locate the list in which you last added an asset to the letter. 
2. Unlock the order of all lists in the letter. 
   1. Locate and open the relevant list asset. 
   2. Click the Lock Order icon to unlock the order of assets in the list. (An unlocked lock icon signifies unlocked order of list assets.)
   3. Click Save.

Preview the draft letter again. 

Additional information

This error occurs when you reload a saved draft letter that has a list with its order locked and library access enabled.

The following steps cause this error:

1. In the Create Correspondence UI, open the letter with a list that has locked order and library access enabled.
2. Add an asset to the list from the content library. 
3. Create a draft or save the letter as a draft.
4. Reload the letter, select some deselected asset in the relevant list (the list to which you added an asset from the content library), and update the draft. 
5. Now if you try to reload, you get this error.