I'm running three repositories (laptop, usb connected to laptop, local server) that are connected via ssh access. Running the webapp on both laptop and server, I'm quite frequently seeing in both webapps:

 warning
Pusher crashed: fd:56: hPutStr: illegal operation (handle is closed)

Pushing the "Restart thread" button sometimes dismisses the warning, sometimes it immediatly comes back even when trying several times. A similar warning sometimes shows up for a Netwatcher thread.

Not sure but when that crash occurs tranfers between the repos seem to get stalled.

Server: git-annex 7.20190129-2~bpo9+1 on debian stretch Laptop: git-annex 7.20190129-3 on debian testing

Log snippet:

[2019-09-07 14:10:30.330041206] Committer: Adding jmg_0578.jpg5895 jmg_0578.jpg
add incoming/5d/jmg_0578.jpg [2019-09-07 14:10:30.358484399] Committer: Committing changes to git
(recording state in git...)
[2019-09-07 14:13:01.986780732] Pusher: Syncing with usbimg, cube_media_srv_img 
Pusher crashed: fd:56: hPutStr: illegal operation (handle is closed)
[2019-09-07 14:13:02.009823288] Pusher: warning Pusher crashed: fd:56: hPutStr: illegal operation (handle is closed)
[2019-09-07 14:13:49.112731437] RemoteControl: Syncing with cube_media_srv_img 
(merging synced/git-annex into git-annex...)
fd:56: hPutStr: illegal operation (handle is closed)
fd:56: hPutStr: illegal operation (handle is closed)
From ssh://git-annex-cube-flixh_22_.2Fmedia.2Fsrv.2Fimg/media/srv/img
   3c9104b770..cea5c2f058  annex/direct/master -> cube_media_srv_img/annex/direct/master
   71006e08a7..536584bdfa  git-annex  -> cube_media_srv_img/git-annex
fd:56: hPutStr: illegal operation (handle is closed)
[2019-09-07 14:15:58.002820518] Committer: Adding jmg_0592...ftool_tmp
[2019-09-07 14:15:59.526375687] Committer: Adding jmg_0592...ftool_tmp jmg_0592.cr2
add incoming/5d/jmg_0592.cr2 [2019-09-07 14:15:59.599057025] Committer: Committing changes to git
(recording state in git...)
[2019-09-07 14:15:59.670107852] Pusher: Syncing with usbimg, cube_media_srv_img 
Pusher crashed: fd:56: hPutStr: illegal operation (handle is closed)
[2019-09-07 14:15:59.683904185] Pusher: warning Pusher crashed: fd:56: hPutStr: illegal operation (handle is closed)
[2019-09-07 14:18:09.282924907] Committer: Adding CI1026+1375.JPG5895