Explorer or Photos fails to open JPEG saved to private folder by other user

This may or may not be related to Explorer's window to the KBFS folder attempting to open the file to create a thumbnail, but I found that I could not open a JPEG that was shared with me, and examination with a hex editor revealed that the resulting JPEG file was entirely null bytes. It also did not vanish from the folder when the other party deleted it, but I assume that is normal and that it should have transferred ownership of the file to me, but the file on my end remained null bytes until I deleted it.

I cannot seem to reproduce it however. Maybe it had something to do with network delay downloading the file slower than Explorer expected it to appear? This time, I already had it downloaded to one of my local machines before attempting to view it on the Windows machine, and it successfully opened.

Is a log still useful?

The report points to the Windows Explorer integration and the KBFS folder, where a shared JPEG became all null bytes and possibly remained after deletion. Start by reproducing the shared-file/open flow while collecting a log; done means the file-content and deletion behavior are verified and the failing path is identified.

Written by the indexing model from the issue text.