# Causes of run-time errors for data logging

At run time the application logs errors to FactoryTalk Diagnostics about data logging under these circumstances:

- If for any reason communications between the data log model and the data log file fail or are interrupted, data logging will stop and will not be restored until the application is restarted. The application will log an error.
- When your project starts at run time, if any of the tags specified in the current data log model do not exist, the application logs an error.
- If the data log file is corrupted or invalid, the file is deleted and recreated, and the application logs an error.
- If the data is not being logged to a folder location on the run-time computer, but to a remote computer on a network, the run-time computer and the remote computer must be on the same domain. Otherwise, the log folder cannot be created and the application logs an error.
- If logging to an invalid path, the log folder cannot be created, and the application logs an error. One of the reasons that the path may be invalid is that the top-level folder of the path must be shared.
- If the storage device becomes full due to lack of disk space, data logging stops, and the application logs an error. When sufficient disk space becomes available, data logging continues, but the data that would have been logged during the intervening time cannot be retrieved.
- If there is not enough disk space at application startup, the data log model does not start when the application starts, and the application logs an error.
- If the data log model contains an invalid tag type, e.g., a string tag, the application logs an error and the tag is put off-scan.

## See also

About data logging

The Data Log Model editor