QuickBooks Error -6155, 0 -- Fixing Read-Only and Access Denied Company File Open Failures

QuickBooks error -6155, 0 blocks company file access due to read-only attributes or insufficient Windows permissions; our engineers walk through each trigger and resolution.

QuickBooks Error -6155, 0 is one of the more straightforward 6000-series errors our engineers encounter, but it can still bring accounting work to a halt. The error fires at the moment QuickBooks Desktop attempts to open a company file and determines that it cannot obtain the level of file access it requires. In nearly every case the underlying cause is either a read-only flag on the company file itself or a Windows permission issue affecting the folder where the file is stored. Resolving it requires identifying which trigger applies and then correcting the file or folder attributes so QuickBooks can open the file normally.

What the Error Message Says

The full message displayed by QuickBooks Desktop reads:

"Error -6155, 0: QuickBooks could not open the file or could not read the data from the file."

In some environments the message may also reference the specific company file name and path. The error code is always presented as a paired value (-6155, 0), where -6155 identifies the file-access failure and 0 indicates no sub-error was returned.

What the Code Means

Error -6155, 0 signals that QuickBooks Desktop successfully located the company file on disk but was denied the read-write access needed to open it for a working session. QuickBooks requires full read-write access to the .QBW file and the hosting folder. When the operating system reports that the file is locked, marked read-only, or that the current Windows user lacks sufficient NTFS permissions, QuickBooks aborts the open operation and returns this error.

What Triggers It

Our engineers see three primary triggers, listed here in order of frequency:

1. The company file or its folder is marked read-only. This can happen after a file is copied from optical media, restored from certain backup tools, or placed on a network share with restrictive default permissions.

2. The logged-in Windows user lacks full-control permissions on the folder containing the company file. This is common when the file resides on a server or secondary workstation and the user account has not been granted explicit folder rights.

3. Another process is holding a lock on the file. A prior QuickBooks crash, a backup application scanning the file, or antivirus real-time protection can leave a lock that prevents a clean open.

How to Fix It

Scenario 1: The company file is marked read-only

1. Close QuickBooks Desktop on all workstations.
2. Open File Explorer and navigate to the folder containing the .QBW file.
3. Right-click the company file and select Properties.
4. In the General tab, look at the Attributes section. If Read-only is checked, uncheck it.
5. Click Apply, then OK.
6. Also clear the read-only attribute on the folder itself: right-click the folder, select Properties, uncheck Read-only, click Apply, and when prompted confirm that the change applies to all subfolders and files.
7. Relaunch QuickBooks and open the company file.

Scenario 2: The Windows user lacks folder permissions

1. Close QuickBooks Desktop.
2. Right-click the folder containing the company file and select Properties.
3. Go to the Security tab and click Edit.
4. Select the current user (or the Users group) from the list.
5. In the permissions panel, check the box for Full control under the Allow column.
6. Click Apply, then OK, and close the Properties dialog.
7. Repeat this on the workstation hosting the file if it differs from the current machine.
8. Open QuickBooks and attempt to open the company file again.

Scenario 3: Another process is locking the file

1. Restart the computer hosting the company file. This clears most stale locks from crashed QuickBooks sessions.
2. After restart, temporarily disable antivirus real-time scanning on the company file folder if the security software allows folder exclusions.
3. Confirm no backup software is actively running against the .QBW file.
4. Open QuickBooks and try opening the file.

How to Prevent It Recurring

To keep this error from returning, our engineers recommend storing the company file in a dedicated folder where the QuickBooks database service and all QuickBooks users have explicit full-control permissions. Avoid copying company files from CDs, DVDs, or USB drives without clearing inherited read-only attributes afterward. If the file lives on a network share, verify that the share-level permissions grant full control to all QuickBooks users in addition to the NTFS folder permissions. Finally, configure antivirus software to exclude the company file folder from real-time scanning so that security software never locks the .QBW file during a backup or open operation.