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+### Please describe the problem.
+
+While dropping 19 unused files from an annex, I got this error:
+
+    error: invalid object 100644 c873416e78db4dd94b6ab40470d6fe99b2ecb8bd for '002/0a6/SHA256E-s427690--03aeabcde841b66168b72de80098d74e047f3ffc832d4bbefa1f2f70ee6c92f8.jpg.log'
+    fatal: git-write-tree: error building trees
+    git-annex: failed to read sha from git write-tree
+
+I've actually seen this before, a few months ago.
+
+### What steps will reproduce the problem?
+
+I have no idea, but once it happens I can't interact with unused files anymore.  Also, `git annex fsck` now reports this same problem as well.
+
+### What version of git-annex are you using? On what operating system?
+
+git-annex version: 4.20130815, OS X 10.8.4