Proper status messages
Accounts go into "Waiting for {x} other folder{s}...." and the tray icon displays "undefined state". The F12 log does sometimes display endless checking for rename e.t.c. before finally (maybe) starting a sync
Client version: 2.5.1 and daily as of 05-april-2019
Operating system: Windows 10 x64 1809 fully up to date
OS language: en_GB
Installation path of client: C:Program Files (x86)Nextcloud
I have the same issue with 2 accounts on linux, version:
/usr/bin/nextcloud --version
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
Nextcloud version 2.5.2git
Using Qt 5.11.3, built against Qt 5.11.1
Using 'OpenSSL 1.1.1b 26 Feb 2019'
EDIT: I realized that switching account tabs on client and hitting "Restart sync" makes it temporarily work, it syncs, but goes back to that "Waiting for 1 other folder(s)" message. Sometimes it just says "Waiting..." instead.
Noticed I'm getting this on a newly installed Linux box.
Sync eventually starts, but I've had it stuck in this state for a couple of hours before there's any activity.
Seeing the same on my system.
Windows 8.1
OS-Language: en_us
NextCloud Desktop Client 2.6.4 stable
NextCloud Server: 18.0.1



As per the screenshot I'm using 2 different NextCloud servers. The sync seems to work fine - just a user experience issue IMHO.
I can confirm the same issue on MacOS. As others mention, I have accounts on two different servers.
I am just facing this too on latest NC20, and latest client on Ubuntu 20.04. The only revelent log I find is on the client, nothing at server level:
2020-12-03 14:26:07:916 [ info nextcloud.gui.folder.manager ]: Scheduling folder "1" because it has been 7849545 ms since the last sync
2020-12-03 14:26:07:916 [ info nextcloud.gui.folder.manager ]: Schedule folder "1" to sync!
2020-12-03 14:26:07:917 [ info nextcloud.gui.folder.manager ]: Sync for folder "1" already scheduled, do not enqueue!
2020-12-03 14:26:07:917 [ info nextcloud.gui.folder.manager ]: Scheduling folder "2" because it has been 7848209 ms since the last sync
2020-12-03 14:26:07:917 [ info nextcloud.gui.folder.manager ]: Schedule folder "2" to sync!
2020-12-03 14:26:07:917 [ info nextcloud.gui.folder.manager ]: Sync for folder "2" already scheduled, do not enqueue!
2020-12-03 14:26:12:919 [ info nextcloud.gui.folder.manager ]: Scheduling folder "1" because it has been 7854548 ms since the last sync
2020-12-03 14:26:12:919 [ info nextcloud.gui.folder.manager ]: Schedule folder "1" to sync!
2020-12-03 14:26:12:920 [ info nextcloud.gui.folder.manager ]: Sync for folder "1" already scheduled, do not enqueue!
2020-12-03 14:26:12:920 [ info nextcloud.gui.folder.manager ]: Scheduling folder "2" because it has been 7853212 ms since the last sync
2020-12-03 14:26:12:920 [ info nextcloud.gui.folder.manager ]: Schedule folder "2" to sync!
2020-12-03 14:26:12:921 [ info nextcloud.gui.folder.manager ]: Sync for folder "2" already scheduled, do not enqueue!
2020-12-03 14:26:17:919 [ info nextcloud.gui.folder.manager ]: Scheduling folder "1" because it has been 7859549 ms since the last sync
2020-12-03 14:26:17:920 [ info nextcloud.gui.folder.manager ]: Schedule folder "1" to sync!
2020-12-03 14:26:17:920 [ info nextcloud.gui.folder.manager ]: Sync for folder "1" already scheduled, do not enqueue!
2020-12-03 14:26:17:920 [ info nextcloud.gui.folder.manager ]: Scheduling folder "2" because it has been 7858212 ms since the last sync
2020-12-03 14:26:17:920 [ info nextcloud.gui.folder.manager ]: Schedule folder "2" to sync!
2020-12-03 14:26:17:921 [ info nextcloud.gui.folder.manager ]: Sync for folder "2" already scheduled, do not enqueue!
2020-12-03 14:26:22:919 [ info nextcloud.gui.folder.manager ]: Scheduling folder "1" because it has been 7864549 ms since the last sync
2020-12-03 14:26:22:920 [ info nextcloud.gui.folder.manager ]: Schedule folder "1" to sync!
2020-12-03 14:26:22:920 [ info nextcloud.gui.folder.manager ]: Sync for folder "1" already scheduled, do not enqueue!
2020-12-03 14:26:22:920 [ info nextcloud.gui.folder.manager ]: Scheduling folder "2" because it has been 7863212 ms since the last sync
2020-12-03 14:26:22:920 [ info nextcloud.gui.folder.manager ]: Schedule folder "2" to sync!
2020-12-03 14:26:22:921 [ info nextcloud.gui.folder.manager ]: Sync for folder "2" already scheduled, do not enqueue!