Open the original configuration file in or Visual Studio Code (not Windows Notepad—it hides encoding errors).

The error occurs after a scheduled automatic update.

The "Loading data failed, check the configuration file" error in usually stems from incorrect file paths, missing database connections, or corrupted configuration XMLs. Quick Fixes for TecDoc Errors

Inside the configuration file, locate the ConnectionString or DataSource parameter. It will look similar to one of these:

The following is a very simplified example in YAML, illustrating some basic configuration elements:

Open the Windows Control Panel, select , and remove TecDoc completely.

For cloud-based TecAlliance services, ensure your LAN connection is stable to avoid timeout errors during data loading. Conclusion

Treat your TecDocClient.config like source code. Save known-good versions in a Git repository or a dated folder ( Config_2025_01_Working ). When an update breaks the file, you can roll back in 30 seconds.