Quick Fields has a few different types of error logs, depending on the type of error. If you're looking for history of what happened during a scan such as errors related to image enhancements or metadata, you can view those in the tasks pane or the output pane. If you're concerned that there is an error in the application itself which may represent a bug or installation issue, I'd recommend viewing the application errors pane. 

If you're using Quick Fields Agent, you can also view any errors that occurred by viewing the instance history.