Hi Prajk,
Based on your description, I recommend to check if there are any ItemAdded event receiver or workflows which are triggered when an item is created to update the document properties in the library.
If there is any ItemAdded event receiver on the library, I recommend to wait for ItemAdded to finish before the ListFieldIterator control residing on EditForm.aspx loads (Its the ListFieldIterator which displays the Items fields ).
http://blogs.msdn.com/b/manuj/archive/2009/09/22/itemadded-event-on-document-library-the-file-has-been-modified-by-on-error.aspx
If there is any workflow on the library, I recommend to add a Pause for Duration step at the beginning of the workflows.
If above cannot work, please check ULS log for detailed error message.
For SharePoint 2013, by default, ULS log is at C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\15\LOGS.
Best regards.