What happens if you tick the “Auto” box?
It would definitely be better to save your LayOut and any reference files locally. If you must save them to DropBox do that after successfully saving locally. Copy the files to the folder in DropBox.
Although some users don’t have problems working with files saved directly to the cloud, the forum is full of threads in which users have wound up with fatally in corrupted files due to that practice. It’s such a simple thing to save and work on internally saved files that there’s no good reason to take the risk of losing hours of effort by working on remotely saved files.
What operating system are you using? Please complete your forum profile.