# problem with reading raw data **URL:** \ **Category:** Mailing List Archive (read-only)\ **Tags:** list-archive\ **Created:** [June 16, 2019, 8:07pm UTC](https://mne.discourse.group/t/problem-with-reading-raw-data/1868 "2019-06-16T20:07:07Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\ **Post date:** [June 16, 2019, 8:07pm UTC](https://mne.discourse.group/t/problem-with-reading-raw-data/1868/1 "2019-06-16T20:07:07Z")
External Email - Use Caution Hello, I have trouble reading some of my raw data files. They seem pretty random -- two are empty room recordings from two different participants recorded at the end of the session, three are task files, while the other files are fine. The error is "file does not start with a file id tag". Below are the details. Could you help me with this? Thank you very much! Link to one of the data files: [https://drive.google.com/open?id=1hwOH0Gh0KOqFpFl0-4HHlr6oZliROaL8](https://drive.google.com/open?id=1hwOH0Gh0KOqFpFl0-4HHlr6oZliROaL8) Output: Opening raw data file EmptyRoom\_raw.fif... ---------------------------------------------------------------------------ValueError                                Traceback (most recent call last)\ in \ 6 fname\_projs = "erm-proj.fif" 7 fname\_erm\_wproj = "EmptyRoom\_wproj\_raw.fif"----\> 8 raw\_erm = mne.io.read\_raw\_fif(fname\_erm, preload=True) 9 raw\_erm.add\_proj([],remove\_existing=True) 10 raw\_erm.info['bads'] = ['MEG0432','MEG2233','MEG2543'] ~/anaconda3/lib/python3.7/site-packages/mne/io/fiff/raw.py in read\_raw\_fif(fname, allow\_maxshield, preload, verbose) 468 """   469 return Raw(fname=fname, allow\_maxshield=allow\_maxshield,--\> 470 preload=preload, verbose=verbose)\ in \_\_init\_\_(self, fname, allow\_maxshield, preload, verbose) ~/anaconda3/lib/python3.7/site-packages/mne/utils/\_logging.py in wrapper(\*args, \*\*kwargs) 87 with use\_log\_level(verbose\_level): 88 return function(\*args, \*\*kwargs)---\> 89 return function(\*args, \*\*kwargs) 90 return FunctionMaker.create( 91 function, 'return decfunc(%(signature)s)', ~/anaconda3/lib/python3.7/site-packages/mne/io/fiff/raw.py in \_\_init\_\_(self, fname, allow\_maxshield, preload, verbose) 83      raw, next\_fname, buffer\_size\_sec = \ 84 self.\_read\_raw\_file(next\_fname, allow\_maxshield,---\> 85                      preload, do\_check\_fname) 86 do\_check\_fname = False 87 raws.append(raw) \ in \_read\_raw\_file(self, fname, allow\_maxshield, preload, do\_check\_fname, verbose) ~/anaconda3/lib/python3.7/site-packages/mne/utils/\_logging.py in wrapper(\*args, \*\*kwargs) 87 with use\_log\_level(verbose\_level): 88 return function(\*args, \*\*kwargs)---\> 89 return function(\*args, \*\*kwargs) 90 return FunctionMaker.create( 91 function, 'return decfunc(%(signature)s)', ~/anaconda3/lib/python3.7/site-packages/mne/io/fiff/raw.py in \_read\_raw\_file(self, fname, allow\_maxshield, preload, do\_check\_fname, verbose) 151 whole\_file = True 152 fname\_rep = \_get\_fname\_rep(fname)--\> 153 ff, tree, \_ = fiff\_open(fname, preload=whole\_file) 154 with ff as fid: 155 # Read the measurement info \ in fiff\_open(fname, preload, verbose) ~/anaconda3/lib/python3.7/site-packages/mne/utils/\_logging.py in wrapper(\*args, \*\*kwargs) 87 with use\_log\_level(verbose\_level): 88 return function(\*args, \*\*kwargs)---\> 89 return function(\*args, \*\*kwargs) 90 return FunctionMaker.create( 91 function, 'return decfunc(%(signature)s)', ~/anaconda3/lib/python3.7/site-packages/mne/io/open.py in fiff\_open(fname, preload, verbose) 129 # Check that this looks like a fif file 130 if tag.kind != FIFF.FIFF\_FILE\_ID:--\> 131 raise ValueError('file does not start with a file id tag')    132 133 if tag.type != FIFF.FIFFT\_ID\_STRUCT: ValueError: file does not start with a file id tag Best, Xiaoping