What fails is the design of the frequency filter.
Please post the following screen captures, for helping us debugging your issue:
- The options window of the detection process
- The file you are processing (signals shown when opened with a double-click)
- The Brainstorm window showing:
- the database explorer showing the files you are processing ,
- the Record tab showing the list of events in the file
- the time window panel showing the signal duration and frequency