Ensure the server name in the config file matches your current SQL instance (e.g., localhost\TECDOC or an IP address).
If you updated the executable file but didn't update the data files (or vice versa), the configuration file will fail to map the new tables. tecdoc loading data failed check the configuration file
If these steps don't work, the configuration file itself might be corrupted beyond manual repair. In this case, renaming the old config file to config_old.ini and restarting the application may force it to generate a fresh, working template. Ensure the server name in the config file