The configuration file contains a connection string (e.g., Server=localhost;Database=TecDocData;UID=tecdoc_user;PWD=...). If the server name changed, the database was renamed, or the password expired, the client cannot load data.
Signature symptom: The error appears instantly after clicking "Load Data."
| Scenario | Best Immediate Action |
| :--- | :--- |
| After a Windows Update | The update reset file associations. Right-click config file > Properties > Unblock. |
| After Antivirus Update | Add the entire TecDoc folder to the AV exclusions list. Restore quarantined .dll files. |
| After Moving Data to a New SSD | You changed the drive letter. Open config in Notepad. Replace D:\TecDoc\Data with E:\TecDoc\Data. |
| Using TecDoc WebService (API) | The error is on the server side. Check web.config for malformed <connectionStrings>. Validate your API token. |
| Offline USB Dongle Version | The dongle driver crashed. Reinstall HASP/Sentinel drivers. The config file checks the dongle ID first. |
Open Windows Explorer and manually navigate to the DataPath value from the config file. loading data failed check the configuration file tecdoc best
This is a very common cause. If you have an external hard drive or a virtual drive where the TecDoc data is stored:
Inspect the configuration file
Enable verbose/debug mode
Test connectivity
Verify credentials and tokens
Check TLS/SSL and certificates
Confirm file/data integrity
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Validate environment overrides