This is a very specific SQL Compact (SQL CE) transaction error, “This SqlCeTransaction has completed; it is no longer usable.”

In plain English:
The program started a database transaction, it failed mid-process, and then tried to keep using that same transaction. SQL CE doesn’t allow that, so it crashes.

This is not a data entry mistake — it’s almost always caused by:

  • database corruption or
  • permissions / file locking or
  • antivirus / sync software interfering with the .sdf database file

Most common causes (in order of likelihood)

1 Database file is locked or partially corrupted

Very common if:

  • Program closed unexpectedly
  • Windows update happened
  • Database is on OneDrive / Dropbox / network share

2 Program not running with enough permissions

SQL CE needs full read/write access to its database folder.

3 Antivirus or ransomware protection blocked the write

Windows Defender’s “Controlled Folder Access” is a huge culprit.

Fix this step-by-step (do these in order)

Before proceeding, please create a backup file, but do not overwrite any of the previous backup, you will need those.

✅ Step 1: Close everything

  • Close MyInvoices & Estimates
  • Make sure no other users are logged into it

✅ Step 2: Run as Administrator

Right-click the program shortcut → Run as administrator
  Try the exact action that caused the error.

If it works → permissions were the issue.

Step 3: Check database location (VERY important)

Default location: C:\Users\[Username]\Documents\MyInvoices\

Then:

  • Right-click the folder → Properties
  • Make sure Read-only is NOT checked
  • Security tab → Users should have Full Control

✅ Step 4: Antivirus / Defender check

Temporarily test by:

  • Turning off antivirus briefly
  • OR add an exclusion for:
    • Program folder
    • Database folder (C:\Users\[Username]\Documents\MyInvoices\)

If the error stops → that was it.

✅ Step 5: Restore from backup or Replace Database file

the next step is usually:

  • Restore from the most recent backup before the error occurred
  • Or replace the *.mied with a known-good copy

⚠️ Important things NOT to do

  • Don’t keep clicking Continue — it makes corruption worse
  • Don’t run it from OneDrive/Dropbox
  • Don’t open the same database from two PCs at once

Next step: please submit a technical support ticket via https://support.avanquest.com/support/tickets/new, and include the following information:

  1. Where is the database stored? (local PC, server, OneDrive, etc.)
  2. When does the error happen? (save invoice, open estimate, print, etc.)
  3. Is this single-user or networked?

That will help us to troubleshoot, to find a solution.