# Assertion error when running	mne.io.read\_raw\_brainvision

**URL:** <https://mne.discourse.group/t/assertion-error-when-running-mne-io-read-raw-brainvision/1006>\
**Category:** Mailing List Archive (read-only)\
**Tags:** list-archive\
**Created:** [April 22, 2016, 8:18pm UTC](https://mne.discourse.group/t/assertion-error-when-running-mne-io-read-raw-brainvision/1006 "2016-04-22T20:18:04Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [April 22, 2016, 8:18pm UTC](https://mne.discourse.group/t/assertion-error-when-running-mne-io-read-raw-brainvision/1006/1 "2016-04-22T20:18:04Z")

</div>

Hi,

I'm trying to open a vhdr file in Python. When I do

raw = mne.io.read\_raw\_brainvision(\<filename\>)

I get this error:  
Traceback (most recent call last):  
&nbsp;&nbsp;File "/usr/pubsw/packages/python/anaconda/lib/python2.7/site-packages/IPython/core/interactiveshell.py",  
line 3035, in run\_code  
&nbsp;&nbsp;&nbsp;&nbsp;exec(code\_obj, self.user\_global\_ns, self.user\_ns)  
&nbsp;&nbsp;File "\<ipython-input-4-1ae38f69fbbe\>", line 1, in \<module\>  
&nbsp;&nbsp;&nbsp;&nbsp;mne.io.read\_raw\_brainvision(filename)  
&nbsp;&nbsp;File "/usr/pubsw/packages/python/anaconda/lib/python2.7/site-packages/mne/io/brainvision/brainvision.py",  
line 624, in read\_raw\_brainvision  
&nbsp;&nbsp;&nbsp;&nbsp;preload=preload, verbose=verbose)  
&nbsp;&nbsp;File "\<string\>", line 2, in \_\_init\_\_  
&nbsp;&nbsp;File "/usr/pubsw/packages/python/anaconda/lib/python2.7/site-packages/mne/utils.py",  
line 541, in verbose  
&nbsp;&nbsp;&nbsp;&nbsp;return function(\*args, \*\*kwargs)  
&nbsp;&nbsp;File "/usr/pubsw/packages/python/anaconda/lib/python2.7/site-packages/mne/io/brainvision/brainvision.py",  
line 80, in \_\_init\_\_  
&nbsp;&nbsp;&nbsp;&nbsp;info, self.\_eeg\_info, events = \_get\_eeg\_info(vhdr\_fname, eog, misc)  
&nbsp;&nbsp;File "/usr/pubsw/packages/python/anaconda/lib/python2.7/site-packages/mne/io/brainvision/brainvision.py",  
line 406, in \_get\_eeg\_info  
&nbsp;&nbsp;&nbsp;&nbsp;assert l == 'Brain Vision Data Exchange Header File Version 1.0'  
AssertionError

How can I debug this? I think there's nothing wrong with the vhdr file  
itself because I have been able to load it and process it in Matlab.

Thanks,

Gladia  
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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [April 22, 2016, 11:34pm UTC](https://mne.discourse.group/t/assertion-error-when-running-mne-io-read-raw-brainvision/1006/2 "2016-04-22T23:34:39Z")

</div>

I believe this issue has been fixed in latest master, can you give it a try?

Eric

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [April 23, 2016, 12:38am UTC](https://mne.discourse.group/t/assertion-error-when-running-mne-io-read-raw-brainvision/1006/3 "2016-04-23T00:38:56Z")

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Hi Eric,

Do I get the latest version by running $ pip install mne ?upgrade in  
python? I did this in pycharm and I got 'invalid syntax'.

Best,  
Gladia

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [April 23, 2016, 8:31am UTC](https://mne.discourse.group/t/assertion-error-when-running-mne-io-read-raw-brainvision/1006/4 "2016-04-23T08:31:24Z")

</div>

hi,

as explained on the readme [1] you need to do:

"  
for the latest development version (the most up to date):

pip install -e git+https://github.com/mne-tools/mne-python#egg=mne-dev --user  
"

in a terminal.

Do not type it in the python interpreter of pycharm but in a console/terminal.

HTH  
Alex

[1] [https://github.com/mne-tools/mne-python](https://github.com/mne-tools/mne-python)