Eclipse: "'Periodic workspace save.' has encountered a pro‍blem."

Question

I'm using Eclipse Indigo on Mac 10.7.4. While working, I get these periodic, annoying dialogs

'Periodic workspace save.' has encountered a problem.  Could not write metadata for '/.org.eclipse.jdt.core.external.folders'. /Users/davea/Dropbox/workspace/.metadata/.plugins/org.eclipse.core.resources/.projects/.org.eclipse.jdt.core.external.folders/.markers.snap (No such file or directory) 

I seem to be able to continue as normal, but I was wondering how I can eliminate these errors.

Answer 1

I had the same problem.

'Periodic workspace save.' has encountered a problem. Could not write metadata for '/External Files'. D:\java\fuentes\.metadata\.plugins\org.eclipse.core.resources\.projects\External Files\.markers.snap (El sistema no puede hallar la ruta especificada)

I created the folder "External Files" and it worked fine. In a few minutes the files ".markers.snap" and ".syncinfo.snap" appeared in this folder and the message didn´t appear any more.