Synchronization error with Nextcloud desktop client

Nextcloud desktop client : 3.5.4
Operating system and version : Windows server 2019

Dear all,

I have set up Nexcloud desktop client on a server to synchronize online files with local files (I want that files created on my online Nextcloud drive go to a drive on my server). Most of the time it works, but regularly I get an error and new file is not synchronized. In addition, the Folder Sync Connection in nextcloud settings shows a red cross, and folder sync is blocked, I have to manually clic on Force sync now to get back a green symbol. I have isolated logfile rows that correspond to the error, I can see disk I/O errors, but I’m having doubts that this is the real problem, disk concerned is a network drive and Windows doesn’t show any error on it.

ownsql.cpp:320 ]:	Sqlite exec statement error: 10 "disk I/O error" in "INSERT OR REPLACE INTO metadata (phash, pathlen, path, inode, uid, gid, mode, modtime, type, md5, fileid, remotePerm, filesize, ignoredChildrenRemote, contentChecksum, contentChecksumTypeId, e2eMangledName, isE2eEncrypted, lock, lockType, lockOwnerDisplayName, lockOwnerId, lockOwnerEditor, lockTime, lockTimeout) VALUES (?1 , ?2, ?3 , ?4 , ?5 , ?6 , ?7,  ?8 , ?9 , ?10, ?11, ?12, ?13, ?14, ?15, ?16, ?17, ?18, ?19, ?20, ?21, ?22, ?23, ?24, ?25);"
ownsql.cpp:322 ]:	IOERR extended errcode:  778
ownsql.cpp:324 ]:	IOERR system errno:  59
owncloudpropagator.cpp:281 ]:	Could not complete propagation of "tows-entretien-wc-vevey_20220819064410146.jpg" by OCC::PropagateDownloadFile(0x21bba1ad5a0) with status OCC::SyncFileItem::FatalError and error: "Error updating metadata: disk I/O error"
usermodel.cpp:664 ]:	Item  "tows-entretien-wc-vevey_20220819064410146.jpg"  retrieved resulted in  "Error updating metadata: disk I/O error"
usermodel.cpp:639 ]:	Item  "tows-entretien-wc-vevey_20220819064410146.jpg"  retrieved resulted in error  "Error updating metadata: disk I/O error"
syncjournaldb.cpp:249 ]:	ERROR committing to the database: "cannot commit - no transaction is active"
ownsql.cpp:320 ]:	Sqlite exec statement error: 10 "disk I/O error" in "INSERT OR REPLACE INTO key_value_store (key, value) VALUES(?1, ?2);"
ownsql.cpp:322 ]:	IOERR extended errcode:  266
ownsql.cpp:324 ]:	IOERR system errno:  59
folder.cpp:971 ]:	SyncEngine finished with ERROR

Any help will be strongly appreciated. Thanks a lot


the error is pretty clear - write operation didn’t complete for some reason. Most likely you checked your disk already - if not please do… If the disk has no error it must be some other issue e.g. antivirus program holding back the files while analyzing…

Thanks for feedback. Yes I already checked the disk and the Windows event log, and all is fine. I’m trying to find out what could be this other issue. Antivirus is already checked, and is not the problem. Any other idea is welcome.