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JET_errKeyDuplicate Illegal Duplicate Key: How To Solve IT?

  author
Written By Kumar Raj
Anuraag Singh
Approved By Anuraag Singh
Published On August 25th, 2022
Reading Time 5 Minutes Reading

Summary: This write-up will help users to remove Error-1605 “JET_errKeyDuplicate Illegal Duplicate Key” that is faced by every Exchange user. You can use both the professional and manual solution i.e. Inbuilt Exchange Mailbox Repair Utility – ESEUTIL tool to repair Exchange Mailboxes.

If users are getting more than one error message, it indicates that the user mailbox has been damaged. Most of these errors are related with Mailbox corruption. Then all the Exchange Database files Mailboxes such as user, disconnected, archive, resource, etc… and its data items (emails, task, calendars, notes, contacts, journals) will get corrupted.

There are error codes that lead to a certain level of corruption in Exchange and some of the errors can be resolved by using ESEUTIL which is a built-in Exchange Server Utility. But this tool cannot fix the Jet Engine Error like (JET_errKeyDuplicate Illegal Duplicate Key) which makes the Exchange Database unable to mount again in Exchange Server.

When users try to run the ESEUTIL /p command to solve the database corruption issue. Then the user will encounter this error description: “Operation Terminated with Error -1605 (JET_errKeyDuplicate, Illegal Duplicate Key) after zzzz.zzzz seconds”.

Cause: This error occurred when the given command in the above section failed to recreate the B-tree properly.

This error makes the Exchange Database corrupted and create more problem for the users.

Note: In order to solve this error by using the built-in Exchange Utility, it is recommended for users to take the backup of Volume Shadow Copy (VSS) along with default Microsoft Windows Server backup.

Because when users try to recover the error by using the ESEUTIL tool, it might fix the error but users end up with huge data loss or even in a more worst condition.

If this happens user can also try the professional tool i.e. SysTools EDB Repair tool that will help the user to recover corrupted or damaged Exchange Database File and repair Exchange mailbox of 2019, 2016, 2013, 2010 & below versions in a single shot.

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Steps to Solve “JET_errKeyDuplicate Illegal Duplicate Key” Error

Step 1: Run ESEUTIL.exe tool

Step 2: Check the status of the database. First, see that your Exchange Database is dismounted. Then use the following command:

eseutil /mh 

For Example: eseutil mh d:\newfolder\newfolder.edb

Note: The command to check the status of the database while using Exchange Management Shell: Get-MailboxDatabase –Status

Step 3: Run the repair mode command

eseutil /P 

For Example: eseutil /P c:\exchangeserver\mailboxdata\DB2.edb

Note: The command to repair Exchange Mailbox while using Exchange PowerShell are given below:

For those users who are using Exchange 2010:

exchange 2010 command

Those users who are using Microsoft Exchange 2013 & 2016

exchange 2013 and 2016 command

When the process is over after inserting the repair mode command, users need to use the IsInteg tool to defrag Exchange mailbox database in a simplified way. If users are using the Microsoft Exchange Server 2010 or New-MailboxRepair Request cmdlet for Exchange 2010 SP1 or above versions.

Automated Solution to Resolve JET_errKeyDuplicate Illegal Duplicate Key in Exchange

After all this process there might be a risk of major data loss. Users can also use the EDB File Repair tool that will help the user to load and repair EDB File which is highly corrupted or damaged by using the scan mode option (Quick and Advance scan) of this utility. This dual scanning easily resolves the database corruption Exchange 2010, 2013, 2016 without any loss of data.

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This is the best professional tool that IT admin use to recover permanently deleted mailboxes as well as data items and export the recovered corrupted Exchange mailboxes into the Live Exchange Server. This advanced software is also capable to extract mailbox from EDB file Exchange 2016, 2013, 2010 and export multiple Exchange Database file into PST, EML, PDF, MSG, HTML, MBOX file formats.

User can recover the dismounted and offline .edb file without any difficulty & data loss. Even the naive user also uses this tool without having any technical knowledge and saves users time and effort.

After conversion

Working Steps Of the Software to Resolve this Error

Step 1: Run the recovery manager for Exchange database software > Click on Add File

run the software

Step 2: Load EDB file > Click on Advance Scan to Exchange Database File Corruption > Click on Add button.

load exchange database file

Step 3: Preview and select the Exchange Mailboxes > Click on Export

preview exchange mailboxes

Step 4: Choose the corrupted Exchange Mailboxes that have been recovered > Select the file format to Export the recovered Mailboxes > Click on Browse to set the target location > Click on Export

select corrupted exchange mailbox

Bringing It All Together

This write-up contains all the important information to resolve the “JET_errKeyDuplicate Illegal Duplicate Key” error. User can use any method mentioned here and remove the corruption. Most of the technical users and IT admin prefer the professional solution because the process of doing is very simple and short.

  author

By Kumar Raj

A versatile writer with the vast knowledge of technology helps to reduce the gap between a user and technology. Provides easy and reliable ways to resolve multiple technical issues, which users encounter in their day-to-day life.