eM Client Backup Failure

Have been using eM Client for years with daily automatic backup to a portable hard drive. Noticed the other day that it hadn’t backed up for a few days so tried a manual backup but it failed. I have checked I am on latest version of eM Client and I have tried backing up to internal hard drive (plenty of space) but it just keep failing. Any suggestions please.

Log: 15:03:13 Database backup: Failed
15:03:17 Microsoft.Data.Sqlite.SqliteException (0x80004005): SQLite Error 10: ‘disk I/O error’.
at Microsoft.Data.Sqlite.SqliteException.ThrowExceptionForRC(Int32 rc, sqlite3 db)
at Microsoft.Data.Sqlite.SqliteDataRecord.Read()
at Microsoft.Data.Sqlite.SqliteDataReader.Read()
at MailClient.Storage.Data.DatabaseCopyTool.CopyContents(Table table, Boolean sortDesc)
at MailClient.Storage.Data.DatabaseCopyTool.CopyTableData(Table table)
at MailClient.Storage.Data.DatabaseCopyTool.CopyInternal(String specificTable, Boolean copyIndexesViewsAndTriggers)
at MailClient.Storage.Data.DatabaseCopyTool.CopySchema(String schema)
at MailClient.Storage.Data.DbRepository`1.Backup(String dataStoreLocation, IDbConnection sourceConnection, IDbConnection destinationConnection, CancellationToken token, TransferredSizeUpdated parentProgressTracker)
at MailClient.Storage.Backup.RepositoryBackupTool.DoLiveBackup(DataStore targetDataStore, CancellationToken token, TransferredSizeUpdated parentProgressTracker)
at MailClient.Accounts.ItemRepositories.DoLiveBackup(DataStore targetDataStore, CancellationToken token, TransferredSizeUpdated progressTracker)
at MailClient.Accounts.AccountManager.DoLiveBackup(DataStore targetDataStore, CancellationToken token, AccountNameChanged accountChangeTracker, TransferredSizeUpdated percentTracker)
at MailClient.Scheduler.Tasks.BackupTask.PerformBackup(CancellationToken token, String tempDirectory)
at MailClient.Scheduler.Tasks.BackupTask.DoWork(IWin32Window owner, CancellationToken token, IScheduler scheduler, ReportProgress progressReporter)
at MailClient.Scheduler.Scheduler.<>c__DisplayClass14_0.b__0(Object state)
Table = LocalMailContents
DbLocationDriveType = Fixed
DbLocationFreeDiskSpace = 238595674112
GUIStatus_Exception_Reported = True

jueves 09 febrero 2023 :: 1816hrs (UTC +0100)

1./ Delete eMC from Task Scheduler
2./ Disable Backup in eMC
3./ Reboot eMC
4./ Enable Backup in eMC with your chosen schedule
5./ Reboot eMC
Backup should now work again.

¡Buena suerte!

¡Saludos desde Valencia la soleada en España!



Hablo español, luego portugués e inglés, con conocimiento de varios otros idiomas.

Thanks for your suggestion. Unfortunately, it doesn’t work in this instance. Followed your instructions, then set off a backup, but it failed again.


Try changing the backup location to the default internal drive “Documents / eM Client” folder to test incase you have an actual external disk or external port problem being you are getting a Disk I/O error.

Thanks. I have tried that already. Same disk I/O error message, but I’m not getting any other disk I/O errors from either drive, so I’m at a loss.


What version of eM Client are you running, and what version of Windows do you have ?

A disk I/O error could be anything related to the health of your disk.

Please close eM Client and run a disk check on your C: drive or whatever drive the database is stored on. Also, make sure you have free space on your C: drive and the database drive if different.

When that is done, restart Windows and eM Client and try the backup again.

If that doesn’t help, then you will need to delete the database.

  1. If you have a recent backup, you can delete the current eM Client database, then restore the backup and eM Client should start working again without any problems.

  2. If you don’t have a backup, but all your data is synced with servers, then you can delete the database and start over. After adding your accounts, eM Client will resync with the server.

By default, the database is the complete C:\Users\yourusername\AppData\Roaming\eM Client\ folder. You may have to enable hidden items in Windows Explorer to get there.

EMC 9.2.1577 with Windows 10 Home.

Thanks Gary. Disk check shows no problems and plenty of space. Don’t really want to delete the database when it hasn’t backup up for 2 weeks, but may be my only option.

Is there not some more data in the error? It may have the name of the folder where the disk issue is detected.