Nextcloud version: 11.0.3 (stable)
Operating system and version : Ubuntu 16.4
Apache or nginx version (eg, Apache 2.4.25): Not sure. I installed the Snap from the repo.
PHP version (eg, 5.6): 7.0.20
Client: (Laptop)
Windows 10
Version 2.3.1
Is this the first time you’ve seen this error?: Yes.
Can you reliably replicate it? (If so, please outline steps):
The issue you are facing:
When syncing between my laptop and the server it is failing to update several files. Gives me the following error on my client but nothing on the server:
FilePath: Error transferring URL File Path -chunking-random number - server replied: Precondition failed (An If-Match header was specified and the resource did not exist)
The files have increased in size, but there should be plenty of room, and the files are still less than 2 GB.
The output of your Nextcloud log in Admin > Logging:
Problem happened today, no logs here since 6 days ago.
The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
The output of your Apache/nginx/system log in /var/log/____:
Remember, this information may be requested if it isn’t supplied; for fastest response please provide as much as you can 
Feel free to use a pastebin service, otherwise log files can be indented with 4 spaces on each line to present them in a friendlier way on the forum.