Warning! The undo file length is 1569321556 bytes. Undo will be automatically disabled at 1750000000 bytes to prevent overflow…
Although I’m not sure what an UNDO Overflow would look like, rather than soil the carpets with all those abandoned and rolled back activities, I decided to investigate further. I recommended that the designer saveas to ensure no data was lost and then began an investigation.
- Use Saveas to write the file back to the harddrive or network location in case of a potential fatal error.
- Clear out the temp folder – Use %temp% in the file dialog and delete files found.
- Flush the Undo register – Type Undo – C – All
For more info refer to this Autodesk technical reference.