Sorry for the belated reply. @leilaelam and @mahditaghaddosi can you confirm if your .cnt files are from Neuroscan device or ANTNeuro device? Both manufacturers use a .cnt file extension, but the files are different formats.
If you’re using ANTNeuro device: we have an open issue discussing support for ANTNeuro files: ENH: import ANT Neuro .CNT files (some code available) · Issue #3609 · mne-tools/mne-python · GitHub On that thread, this comment nicely summarizes the currently available workarounds.
If you’re using Neuroscan device: we need a file that causes the error in order to be able to reproduce locally and debug. Can you provide such a file?
Cross-ref to recent, similar post: error mne.io.read_raw_cnt()