Looks like issue has the same root cause. Sync wants to open and sync Office temporary files while office does not like it. While you can't prevent Sync from opening the file (it happens before the ignore list is checked), please verify if "~*" filter is present in your .sync\IgnoreList. If you upgraded from 1.3 it might not be there, as it became default only in 1.4.
I find it very hard to believe that anyone could think that opening a file before determining if it should be ignored is a good idea. Since I'm new here, I will refrain from saying exactly what I think about doing it that way round, but really? Open and only then check if you should have done it? This certainly explains why I've had problems with applications (not the MS Office programs) not being able to open their own files despite those files being excluded.
Related, but slightly different, wouldn't the best way of reading files for sync be to use shadow copy on Windows, so the file can be used as normal while it is being copied by BTSync? This doesn't fix any write conflicts, but it should fix read conflicts.
Ms Office: Don't Have Permission To Write To The Selected Folder
in Sync Troubleshooting
Posted
I find it very hard to believe that anyone could think that opening a file before determining if it should be ignored is a good idea. Since I'm new here, I will refrain from saying exactly what I think about doing it that way round, but really? Open and only then check if you should have done it? This certainly explains why I've had problems with applications (not the MS Office programs) not being able to open their own files despite those files being excluded.
Related, but slightly different, wouldn't the best way of reading files for sync be to use shadow copy on Windows, so the file can be used as normal while it is being copied by BTSync? This doesn't fix any write conflicts, but it should fix read conflicts.