The error in Joplin just gave me this error and advised to post this here. I am using Joplin on Windows with this information
Joplin 2.3.5 (prod, win32)
Client-ID: 895c61b94ca34ebf9f13af84530a0c50
Sync-Version: 3
Profil-Version: 39
Unterstützter Schlüsselbund: Ja
Revision: 819af3c
Error
The sync target could not be upgraded due to an error. For support, please copy the complete content of this page and paste it in the forum: https://discourse.joplinapp.org/
The full error was:
PUT locks/exclusive_desktop_895c61b94ca34ebf9f13af84530a0c50.json: Expected filesize of 89 bytes but read (from Nextcloud client) and wrote (to Nextcloud storage) 0 bytes. Could either be a network problem on the sending side or a problem writing to the storage on the server side. (Exception Sabre\DAV\Exception\BadRequest) (400): <?xml version="1.0" encoding="utf-8"?> <d:error xmlns:d="DAV:" xmlns:s="http://sabredav.org/ns"> <s:exception>Sabre\DAV\Exception\BadRequest</s:exception> <s:message>Expected filesize of 89 bytes but read (from Nextcloud client) and wrote (to Nextcloud storage) 0 bytes. Could either be a network problem on the sending side or a problem writing to the storage on the server side.</s:message> </d:error>
Error: PUT locks/exclusive_desktop_895c61b94ca34ebf9f13af84530a0c50.json: Expected filesize of 89 bytes but read (from Nextcloud client) and wrote (to Nextcloud storage) 0 bytes. Could either be a network problem on the sending side or a problem writing to the storage on the server side. (Exception Sabre\DAV\Exception\BadRequest) (400): <?xml version="1.0" encoding="utf-8"?>
<d:error xmlns:d="DAV:" xmlns:s="http://sabredav.org/ns">
<s:exception>Sabre\DAV\Exception\BadRequest</s:exception>
<s:message>Expected filesize of 89 bytes but read (from Nextcloud client) and wrote (to Nextcloud storage) 0 bytes. Could either be a network problem on the sending side or a problem writing to the storage on the server side.</s:message>
</d:error>
at newError (C:\Users\Florian\AppData\Local\Programs\Joplin\resources\app.asar\node_modules\@joplin\lib\WebDavApi.js:414:11)
at WebDavApi.exec (C:\Users\Florian\AppData\Local\Programs\Joplin\resources\app.asar\node_modules\@joplin\lib\WebDavApi.js:441:11)
at async FileApiDriverWebDav.put (C:\Users\Florian\AppData\Local\Programs\Joplin\resources\app.asar\node_modules\@joplin\lib\file-api-driver-webdav.js:201:10)