CSync unspecified error

c:\Program Files (x86)\switchdrive>switchdrive.exe --logfile c:\Users\andreas\switchdrive_2021_05_28_2.txt

[...]
05-28 09:44:50:164 [ warning sync.database.sql ]:	Sqlite step statement error: 11 "database disk image is malformed" in "SELECT path, inode, modtime, type, md5, fileid, remotePerm, filesize,  ignoredChildrenRemote, contentchecksumtype.name || ':' || contentChecksum FROM metadata  LEFT JOIN checksumtype as contentchecksumtype ON metadata.contentChecksumTypeId == contentchecksumtype.id WHERE phash=?1"
05-28 09:44:50:164 [ warning sync.database ]:	No journal entry found for  "ZHAW_Assistent/FotoFinder/BA19_bmat_02_CoolingStation/2.Recherche/files/104/icon-instagram.svg" Error:  "database disk image is malformed"
05-28 09:44:50:164 [ info sync.database ]:	Closing DB "C:/Users/andreas/switchdrive/._sync_1f3ce89cbf1f.db"
05-28 09:44:50:166 [ warning sync.engine ]:	ERROR during  csync_update :  "CSync unspecified error."
05-28 09:44:50:182 [ info sync.database ]:	Closing DB "C:/Users/andreas/switchdrive/._sync_1f3ce89cbf1f.db"
05-28 09:44:50:182 [ info sync.engine ]:	CSync run took  7183 ms
05-28 09:44:50:182 [ info gui.socketapi ]:	Sending SocketAPI message --> "STATUS:OK:C:\\Users\\andreas\\switchdrive" to QLocalSocket(0x93bb298)
05-28 09:44:50:182 [ info gui.folder ]:	Client version 2.5.4daily20190604 (build 1865)  Qt 5.11.2  SSL  OpenSSL 1.1.1  11 Sep 2018
05-28 09:44:50:182 [ warning gui.folder ]:	SyncEngine finished with ERROR
05-28 09:44:50:182 [ info gui.folder ]:	Folder sync result:  2
05-28 09:44:50:182 [ info gui.folder ]:	the last 3 syncs failed
05-28 09:44:50:182 [ info gui.socketapi ]:	Sending SocketAPI message --> "STATUS:OK:C:\\Users\\andreas\\switchdrive" to QLocalSocket(0x93bb298)
05-28 09:44:50:183 [ info gui.socketapi ]:	Sending SocketAPI message --> "UPDATE_VIEW:C:\\Users\\andreas\\switchdrive" to QLocalSocket(0x93bb298)

ownCloud Client Manual – Appendix C: Troubleshooting
Owncloud Datenbank-Probleme

Download sqlite3: SQLite Download Page, sqlite-tools-win32-x86-3350500.zip

SQLite Commands
Command Line Shell For SQLite

C:\Users\andreas\switchdrive>c:\sqlite-tools-win32-x86-3350500\sqlite3.exe C:/Users/andreas/switchdrive/._sync_1f3ce89cbf1f.db
SQLite version 3.35.5 2021-04-19 18:32:05
Enter ".help" for usage hints.

sqlite> PRAGMA integrity_check;
row 39975 missing from index sqlite_autoindex_metadata_1

sqlite> reindex;

sqlite> PRAGMA integrity_check;
ok

sqlite> .exit