How to Fix Error 15105 and Find the Real Cause

What is Error 15105?

Error 15105 is a reason code inside a SQL Server message. SQL Server tried to show the Windows description of an operating system error and the lookup failed with code 15105. Microsoft describes the code as a missing entry in the Windows resource cache for a language file.

SQL Server shows the message below when a backup fails with error 5.

Cannot open backup device 'E:\Backup\OrdersDB.bak'. Operating system error 5(failed to retrieve text for this error. Reason: 15105).
BACKUP DATABASE is terminating abnormally.

Four parts of the message tell you what happened.

What Causes Error 15105?

Reason 15105 can follow any Windows error code. Ten codes relate to database files and the table lists the Microsoft meaning of every code with the method that fixes it:

Some messages show a hex value like 0x80770006 in place of a small number. Search the Microsoft error list for that value.

Which Facts Need a Check Before Fixing Error 15105?

Check five facts before you edit any permission or file:

• Operation. Note whether the message came from a backup, a restore or an attach because the operations use different accounts and paths.
• Error Number. Note the number before Reason 15105 because the number selects the method.
• File Path. Copy the full path from the message including the file name.
• Service Account. Find the account of the SQL Server service with the query below.
• Backup. Find the newest full backup plus the log backups made after it.

SELECT servicename, service_account, status_desc
FROM sys.dm_server_services;

Search the SQL Server error log for 15105 with the statement below.

EXEC sys.sp_readerrorlog 0, 1, N'15105';

5 Methods to Fix Error 15105 in SQL Server

Five methods fix the problems behind the error. Start with the free methods because they need no database repair.

Confirm your system's compatibility before you download. Recovery software needs .NET Framework 4.5 or higher plus 100 MB of storage and 4 GB of RAM. Supported systems include Windows 11 and 10 plus 8 and 7 along with Server 2016, 2012 R2 and 2008.

Method #1: Decode the Real Windows Error (Free, Start Here)

Error 15105 hides the description of the failure so you look up the number instead. Steps that find the failure are:

• Execute the error log search from the checks above in SSMS to list every 15105 message.
• Find the number after the words Operating system error in the message.
• Open Command Prompt.
• Execute net helpmsg 5 and replace 5 with your number.
• Compare the description with the table in this guide.
• Continue with the method that matches the number.

Note. Microsoft states in its NET HELPMSG command post that the command decodes basic Windows error codes. Find larger numbers in the Microsoft list of system error codes.

Method #2: Grant the Service SID Access to the Folder (Free, Fixes Error 5)

Error 15105 with error 5 shows that Windows refuses access to the file or folder for the SQL Server service. Microsoft names the service SID as the account that needs Full control on the folder with the database files.

• Select the folder that stores the database files and open Properties.
• Open the Security tab and select Edit and then Add.
• Select Locations and choose your computer name.
• Type NT SERVICE\MSSQLSERVER for a default instance or NT SERVICE\MSSQL$InstanceName for a named instance.
• Select Check Names and then OK.
• Tick Allow for Full control and select Apply.
• Execute the failed backup, restore or attach again.

Note. Attach and restore tasks can use the login of the person who executes the statement. Microsoft documents the Process Monitor tool to find the account behind a denied file access. Microsoft lists the full steps in its permission guide for database files.

Method #3: Correct the Path, Name and Free Space (Free, Fixes Errors 2, 3, 21, 112, 123 and 183)

Path or name mistakes cause error 15105 with errors 2, 3, 123 or 183. Errors 21 and 112 point to the volume. Check the path first because that check takes seconds.

• Compare the path in the message with the real location in File Explorer.
• Remove extra spaces and quotation marks from the path and create the missing folder when error 3 names one.
• Choose a new file name when error 183 says the file exists already.
• Open Disk Management and bring the volume online when error 21 says the device is not ready.

List the file paths stored inside a backup before a restore.

RESTORE FILELISTONLY
FROM DISK = N'F:\Backup\OrdersDB.bak';

Check the free space on the volumes that store your database files when error 112 appears.

SELECT DISTINCT vs.volume_mount_point, vs.available_bytes / 1048576 AS free_mb
FROM sys.master_files AS mf
CROSS APPLY sys.dm_os_volume_stats(mf.database_id, mf.file_id) AS vs;

• Free space on the volume or restore the database to a larger volume with the MOVE option.

Note. The volume needs space for the data file and the log file together.

Method #4: Free Files in Use and Start the SQL Writer Service (Free, Fixes Errors 32 and 33)

Another process uses the file when errors 32 or 33 come with error 15105. Snapshot backup tools create backup devices with a GUID name and those tools need the SQL Writer service. Microsoft states that backup applications cannot reach the data files while the service is stopped.

• Open Resource Monitor, select the CPU tab and expand Associated Handles.
• Search for the file name from the message.
• Close the application that uses the file or stop its service.
• Open Services, find SQL Server VSS Writer and select Start when it is stopped.
• Execute the failed task again.

Native backup works while the service is stopped. Use the statement below when you need a backup at once.

BACKUP DATABASE [OrdersDB]
TO DISK = N'F:\Backup\OrdersDB_native.bak'
WITH CHECKSUM, COPY_ONLY;

Note. Microsoft explains in its SQL Writer service post that snapshot based backup tools break when you disable the service.

Method #5: Restore Objects From a Damaged File With EmailDoctor (Paid After Demo)

Damaged database files cause error 15105 with error 1117 or a failed attach of copied files. Choose recovery software when a damaged file has no clean backup. EmailDoctor SQL Database Recovery scans damaged MDF and NDF files and shows the tables and views it finds.

Recovery software handles the file without T-SQL knowledge. Free demo exports save 25 rows from every table and 5 additional objects.

Scan the Damaged File

1. Install the software on a Windows system and start it.
2. Select Open and choose the copy of the MDF file from a healthy volume.
3. Select Quick Scan and let the software detect the SQL Server version.
4. Close the scan message with OK.
5. Expand the tree and select a table to see the recovered rows.

Export the Objects

6. Click Export and choose the Export As SQL Server Database option.
7. Select your server from the list. Choose Windows Authentication for your current account or SQL Server Authentication with a login and password.
8. Choose Create New Database and name it OrdersDB_Recovered.
9. Mark the objects you need and choose With Schema & Data.
10. Click Export and close the Export Completed window.
11. Execute DBCC CHECKDB (N'OrdersDB_Recovered') in SSMS and point your applications to the new database.

    Use Advanced Scan if Quick Scan returns too few objects. Compare both scan modes in our Corrupt MDF File Repair Guide.

Troubleshooting Common Error 15105 Problems

Slow fixes for error 15105 come from five problems:

• No Small Number Appears. The message shows a hex value so search that value in the Microsoft error list.
• Error 5 Returns After You Grant Access. SQL Server uses another login for the file so find that login with Process Monitor.
• Error 112 Appears During a Restore. The destination volume is full so restore with the MOVE option to a larger volume.
• Error 1117 Appears. The disk reports a hardware failure so follow our Disk Error 825 Fix Guide and copy the files at once.
• Attach Fails After the Copy. Damaged pages can exist so execute DBCC CHECKDB and use Method #5 on a copy.

Frequently Asked Questions

Author’s Verdict

Error 15105 hides the real message so the number before Reason is the only clue. Decode that number before you edit anything.

Fix permissions and paths first because they cost nothing and risk no data. Free the file or start the SQL Writer service when another process uses it.

Use EmailDoctor recovery software when the number points to damage and no clean backup exists. Apply fixes to a duplicate database before production.