2024-12-25 18:17:00,733 - INFO - Processing started for file: ./csvfiles/imagine_nouhadata_BandPower2024-12-25,16-32-25-602962.csv
2024-12-25 18:17:00,733 - INFO - Starting data preprocessing...
2024-12-25 18:17:00,738 - ERROR - An error occurred: Invalid data: Invalid key values found: [nan]
Traceback (most recent call last):
  File "E:\NextCloud\Document\pythonFile\main-script.py", line 64, in main
    processed_data = preprocess_eeg_data(
  File "E:\NextCloud\Document\pythonFile\preprocessing.py", line 157, in preprocess_eeg_data
    raise ValueError(f"Invalid data: {message}")
ValueError: Invalid data: Invalid key values found: [nan]