Why antivirus causes this specific error: QuickBooks uses two database service executables — qbdbmgr.exe and qbdbmgrN.exe — to manage company file access. Antivirus products, particularly PC Tools Internet Security, AVG, and ESET NOD32, sometimes flag these as suspicious and either quarantine them (move them out of the QB install folder) or rename them (append _AVG_RESTORED or similar). When QB launches and cannot find these files in their expected location, it returns "your QuickBooks installation may have been modified" with error -6010, -100. Restoring the quarantined files and adding the QB install directory to antivirus exclusions resolves this permanently.

Error code

6010, -100

6xxx Series · Installation Modified

Related: -6000 -82 · -6177 · H-series

What it means

Error 6010-100 means QuickBooks detects that its own program files are different from what they were at installation — something has modified, removed, or blocked one or more QB executable files since the software was installed. The most common modifier is antivirus software, which quarantines or renames QB database service files. Other causes include corrupted updates, incorrect hosting settings, or network access being blocked.

Your company data is safe. Error 6010-100 is a program-level error — your .QBW company file is not affected or damaged by this error.

Antivirus Quarantined QB Files

Most common cause — antivirus software quarantined or renamed qbdbmgrN.exe or qbdbmgr.exe from the QuickBooks install folder. Confirmed by Intuit to be caused by PC Tools Internet Security, AVG, ESET NOD32, and SpyHunter. Check the antivirus quarantine vault first.

File Hosted on Non-Server Computer

The company file is hosted on a workstation instead of the server, or multiple computers have hosting enabled. The error message specifically states "-6010, -100: The company file is hosted by a computer that's not the server."

Corrupted or Incomplete QB Update

A QuickBooks update downloaded and installed incorrectly, replacing some program files with damaged versions or leaving the installation in an inconsistent state. The Install Diagnostic Tool resolves this.

Firewall Blocking QB Database Service

Windows Firewall or a third-party security product blocking QBDSM from starting or communicating. When the database service cannot start, QB cannot access the company file and returns -6010, -100.

Disconnected .ND File

The Network Descriptor (.ND) file is corrupted or disconnected from the company file. When QB cannot read the .ND file, it loses the connection to the database and returns -6010, -100 in some configurations.

Registry Entries Deleted by Cleanup Tools

Registry cleaning or optimizing software removed QuickBooks-related registry entries that QB uses to locate its own files and services. QB detects these missing entries as a modification to its installation.

METHOD 1 Check Antivirus Quarantine and Add QB Exclusions Most common cause — check this first

Antivirus software that quarantines QB database service files is the most common cause of -6010, -100. Restoring the files and adding QB to exclusions resolves this permanently.

METHOD 2 Fix Hosting — Only Server Should Host Multi-user environment — hosting on wrong computer

The error specifically notes "-6010, -100: The company file is hosted by a computer that's not the server." Check all computers — only the server should host. This is the same hosting fix as H101/H303.

METHOD 3 Rename .ND File and Run QBDSM Scan Corrupted or disconnected network descriptor

A stale or damaged .ND file causes QB to lose the database connection producing -6010, -100. Renaming forces regeneration.

METHOD 4 Run QuickBooks Install Diagnostic Tool After corrupted update — fixes Windows components

If the error appeared after a QB update, damaged .NET or C++ components may be preventing QB database services from starting. The Install Diagnostic Tool repairs the Windows components QB depends on.

METHOD 5 Run QuickBooks File Doctor If error persists after above methods

File Doctor addresses both network configuration and minor file damage issues that can contribute to -6010, -100.

METHOD 6 Clean Install QuickBooks All above tried — genuine installation modification

Only if all above methods have failed — and only after adding QB to antivirus exclusions first (Method 1) to prevent the new installation from being quarantined immediately.

The error says to reinstall QuickBooks — should I just do that?

Not as your first step. The error message is generic — it says reinstall because QB detected a modification to its installation, but it cannot tell you what made the modification. If the cause was antivirus quarantining your files (Method 1), reinstalling will result in the antivirus immediately quarantining the same files again. If the cause was a hosting misconfiguration (Method 2), reinstalling does nothing to fix hosting settings. Only if Methods 1–5 have all failed should you proceed to a clean install — and even then, add the QB install folder to your antivirus exclusions before installing, or the same error will return within minutes.

Which antivirus products are most likely to cause Error 6010-100?

Intuit's own documentation specifically names PC Tools Internet Security, AVG Anti-Virus, SpyHunter, and ESET NOD32 as antivirus products that have been confirmed to quarantine or block QuickBooks database service executables. However, any antivirus with aggressive real-time protection or heuristic scanning can trigger this error — particularly after an antivirus signature update that newly flags QuickBooks files as suspicious. If you recently updated your antivirus software or its definitions and 6010-100 appeared the next time you opened QuickBooks, antivirus quarantine is almost certainly the cause.

How do I prevent this error from recurring after fixing it?

Three steps prevent recurrence. First and most important: add the QuickBooks install folder (typically C:\Program Files\Intuit\QuickBooks [Year]) to your antivirus exclusion list — this prevents future quarantining of QB files after antivirus signature updates. Second: set QuickBooks Database Server Manager to Automatic startup in Windows Services so it survives server restarts without manual intervention. Third: avoid registry cleaning tools — products that clean or optimise the Windows registry frequently remove QuickBooks registry entries, which triggers the "installation may have been modified" error. Registry cleaners provide no meaningful benefit and cause disproportionate harm to complex software installations like QuickBooks.