QuickBooks Error 6170, Damaged Company File Over a Network

Error 6170 blocks QuickBooks Desktop from opening a company file stored on a network share. Our engineers explain the causes and how to restore access.

When QuickBooks Desktop refuses to open a company file and reports error 6170, the file itself is usually the problem, not the program. The error appears most often when the file sits on a network share or server and something has damaged it or left it in a state the program cannot read. This page covers what the message means, what causes it, and the steps our engineers take to get the file open again.

What does the error message say?

The message you see is typically:

"Error -6170, -82: QuickBooks was unable to open the company file on the host computer. Possible causes include the company file being damaged or the version of QuickBooks used to open the file being older than the version used to create it."

Some installations show a shorter variant that names only the code and the phrase "unable to open the company file." Either way, QuickBooks stops at the point where it tries to read the file's header, before any data loads.

What does error 6170 mean?

The 6000 series covers failures that happen while QuickBooks reads or reaches a company file. Code 6170 points to the file itself: either its internal structure is damaged, or the copy you are opening does not match the version or state QuickBooks expects. It is not a licensing error and not a network permission error in the usual sense, although network conditions are often what damaged the file in the first place.

What triggers it?

Three situations account for nearly every case we see:

1. A company file damaged by an interrupted write, such as a power loss, a forced shutdown, or a dropped network connection while QuickBooks was saving.
2. A version mismatch, where the file was last saved or upgraded in a newer release of QuickBooks than the one now trying to open it.
3. Network instability, where the file is hosted on another machine and slow or interrupted communication corrupts the file's transaction log or leaves the file and its log out of step.

How to fix it

Work through these in order. Stop as soon as the file opens and verifies cleanly.

Step 1: Restore from your most recent backup

If the file is damaged, a recent backup is the fastest and safest route.

1. Copy the backup file (.QBB) from your backup location to the local hard drive of the machine running QuickBooks. Do not restore across the network.
2. In QuickBooks, choose Open or Restore Company, then Restore a backup copy, and follow the prompts.
3. When asked where to save the restored file, choose a local folder, not the network share.
4. Open the restored file and run Verify Data from the File, Utilities menu.

Step 2: Check for a version mismatch

If the file was opened or upgraded in a newer release, an older copy of QuickBooks cannot read it.

1. On the machine that last used the file, press F2 to open the Product Information window and note the release number.
2. On the machine reporting the error, press F2 and compare the release.
3. If the working machine runs a newer release, update QuickBooks on the reporting machine to the same release, then try opening the file again.

Step 3: Repair the file with Verify and Rebuild

Use this when no backup exists or the backup is older than the work you need to keep.

1. Hold Ctrl while opening QuickBooks to reach the No Company Open window.
2. Select the file, hold Alt, and click Open. Keep Alt held until the file opens or the error appears. This suppresses windows that can interfere with the repair.
3. If the file opens, run Rebuild Data, then Verify Data, from the File, Utilities menu.
4. If Rebuild reports that the file cannot be repaired, do not keep retrying. Each attempt on a badly damaged file risks further loss.

Step 4: Copy the file locally before anything else

If the file lives on a network share, copy it and its transaction log (.TLG) to a local folder and try opening it there. This rules out network interference and, in some cases, is enough on its own. Never run Rebuild directly on a file sitting on a network share.

If none of these steps opens the file, the damage is inside the file structure itself. That is repair work rather than troubleshooting, and our engineers handle it as a data recovery job. Have ready the file name and approximate size, the date of your most recent backup, and the QuickBooks release you are running.

How do you prevent it from coming back?

Keep the company file on the host machine and open it across the network only through QuickBooks' own multi-user hosting, never by double-clicking the file in a shared folder. Put the host and server on a uninterruptible power supply so a power cut cannot interrupt a write. Set QuickBooks to back up on close, and keep at least one backup on a different device from the file. Finally, update QuickBooks on every workstation at the same time so a version mismatch never gets the chance to occur.