When a QuickBooks company file stops working, the problem often comes from a damaged TLG file. The TLG file, or Transaction Log file, stores every change made since the last backup. When it gets corrupted, QuickBooks can slow down, crash, or refuse to open. This guide explains how TLG file recovery works, why it matters, and what steps you can take to get your company data back. What a TLG File Does QuickBooks uses two files to store company data: QBW file – This is your main company file with all transactions and lists. TLG file – This logs every change after the last backup. It allows QuickBooks to sync with Intuit Data Services and supports recovery if the QBW file becomes damaged. When the TLG file grows too large or becomes corrupted, QuickBooks can fail to open. Common Causes of TLG File Damage TLG file damage usually comes from one of these situations: Power failure during a QuickBooks session Network drop when using QuickBooks in mu...