Also getting this error message regularly when working with large files (approx. 50MB+) saved on Dropbox. This has been an issue consistently for us for many, many months. I can see it has been for others. Very surprised that I have been unable to find any response to this issue from Trimble.
My company is considering ditching SketchUp and moving to Revit, despite the increased cost, to enable us to work efficiently with larger files. I would rather stay with SketchUp & Layout, which suit our requirements very well in most other respects, but this single issue impacts massively on our productivity.
Trimble - please respond!