About a month ago I posted How to purge DGN linetypes in DWGs but I found an issue resulting in that Autodesk disabled the AutoCAD DGN Clean-up Tool.
Now the AutoCAD DGN Hotfix is released solving this bug and also adding a function that prevents copy and pasting to case bloating.
This Hotfix applies to AutoCAD 2013, to Autodesk AutoCAD 2014, and to related vertical products.
This Hotfix cleans up non-essential data from DWG files that have become bloated while copying and pasting from DWGs containing DGN linetypes. It will also prevent future occurrences of the file bloat issue from occurring when copying/pasting objects within the same drawing, from one file to another, or when attaching a drawing with DGN linetypes to another file as an external reference.
Make sure to read “AutoCAD 2013-2014 DGN Hotfix Readme.pdf” to learn how to install this.