I am currently using AutoCAD 2010 with all the service packs installed and in one specific project, I keep getting INTERNAL ERROR: UNDOCMD 2 or INTERNAL ERROR: UNDOCMD 3. This has been happening for a while now and I have reported it, with no answer. I have tried deleting the UNDO.ac$ files, I have also tried deleting all the possible temp files, all to no avail. Please let me know if you have any other suggestions or ways to fix this problem.
Did you have any solution for your problem. Did it appear again.
Seems that we have the same problem with AutoCAD 2013, with the drawing with a lot Xrefs and layouts.