I have had this problem for months if not a year. I keep hoping that the next release will fix it but it has no effect. Finally I decided to spend some hours trying to get error logs working (I had to conquer how to get into and mess with the system files of my Synology NAS) and submit the bug. I am running version 1.2.82 automatically installed from http://packages.synocommunity.com/ on a pair of Synology NAS boxes. One is an older DS210j (mv6281 ARM processor, 128MB ram), and the other a DS213 (mv6282 ARMv5te 2GHz single processor, 512MB ram). I have one large (40GB) bi-directional share between the two NAS boxes that has this stalling problem. (there are a couple of unidirectional ones that I have been testing to see if they work, and they seem to) I created the debug files with [echo "FFFF" > /usr/local/btsync/var/debug.txt] and after leaving the systems for a couple of hours nothing extra has been written to either of the two files. I have the two large shared folders mapped to separate drives on a windows PC so that I can manually access and modify them. I have tried stopping the syncing, comparing the complete two shared folders with each other using WinMerge.exe and manually deleted or copied over files that didn't sync so that the two folders were identical (except for .SyncID and .SyncIgnore which I have never touched). Then I deleted the all shares and recreated them from scratch and after leaving the system for days (with identical folder systems!), it never completes syncing. Here are screenshots of the stuck state of the two systems: You can see that the box that is supposed to be uploading counts 33496 files, whereas the box that is supposed to be downloading only counts 33380 files, so that 116 files have gone missing somewhere even though winmerge sees and compares them all perfectly (actually winmerge counts 33386 files - I don't know which files are the extra 6!) Could it be a permissions problem? Should I attempt to set all permissions on all files within the folder structure or something? This type of problem is making this package unusable for serious work.