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<div>Hi Daeun,</div>
<div><br>
</div>
<div>What kind of OPM system are you using? </div>
<div><br>
</div>
<div>We've seen an issue with corrupted files a while ago with our Fieldline system when we ran out of disk space during a recording. The header was updated but the data not added resulting in an unreadable file. They have since added a fix that gives you a
warning if you get too close to limit of your disc.</div>
<div><br>
</div>
<div>Best,</div>
<div>Christoph</div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> fieldtrip <fieldtrip-bounces@science.ru.nl> on behalf of Daeun Gwon via fieldtrip <fieldtrip@science.ru.nl><br>
<b>Sent:</b> Wednesday, November 26, 2025 5:45<br>
<b>To:</b> fieldtrip@science.ru.nl <fieldtrip@science.ru.nl><br>
<b>Cc:</b> Daeun Gwon <danigwon@gmail.com><br>
<b>Subject:</b> [FieldTrip] Issue with Loading OPM FIF Files (fiff_dir_tree_find Failure)</font>
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<p>I hope you are doing well. I am writing to report an issue related to loading our OPM data (FIF format) using both MATLAB (FieldTrip) and Python (MNE).</p>
<p><strong>Issue Summary</strong></p>
<ul>
<li style="margin-left:15px">
<p>Some FIF files recorded in the <em>same experiment session</em> fail to load properly.</p>
</li><li style="margin-left:15px">
<p>The end portion of the data appears truncated when loaded.</p>
</li><li style="margin-left:15px">
<p>This occurs identically in both MATLAB and Python, while certain PCs load all files without any issues. This suggests that the data files themselves are not corrupted.</p>
</li></ul>
<p><strong>Technical Details</strong></p>
<ul>
<li style="margin-left:15px">
<p>In MATLAB, we confirmed that the problem occurs inside the <code>fiff_setup_read_raw</code> function, specifically at line 79 where <code>fiff_dir_tree_find</code> is called.</p>
</li><li style="margin-left:15px">
<p>For files that fail to load, the <code>raw.dir</code> structure contains corrupted values.</p>
<ul>
<li style="margin-left:15px">
<p>Normally, values such as <code>kind</code> and <code>type</code> are consistent integers (e.g., <code>kind = 300</code>, <code>type = 4</code>).</p>
</li><li style="margin-left:15px">
<p>In problematic files, the last entry contains abnormal values (e.g., <code>kind = -113471426</code>, <code>type = -1.103131550000000e+09</code>).</p>
</li></ul>
</li><li style="margin-left:15px">
<p>The implementation of <code>fiff_dir_tree_find</code> does not show abnormalities, making debugging difficult.</p>
</li><li style="margin-left:15px">
<p>We are using the latest FieldTrip version cloned from GitHub and the fieldtrp Web's download</p>
</li></ul>
<p>If you could provide any guidance or suggestions for further debugging, or if you are aware of similar cases, your help would be greatly appreciated.</p>
<p>Thank you very much in advance.</p>
<p>Best regards,<br>
Daeun Gwon</p>
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<span class="x_gmail_signature_prefix">-- </span><br>
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<div dir="ltr"><font size="1"><span style="color:rgb(34,34,34)"><font face="georgia, serif"><span style="font-weight:bold">Daeun Gwon</span><b> </b>(</font></span><span style="color:rgb(34,34,34); font-family:georgia,serif">Ph.D.)</span></font>
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<div><font size="1" color="#666666"><span style="font-family:georgia,serif">Dept. of
</span><font face="georgia, serif">Computer Science and Electrical Engineering</font><br>
</font></div>
<div><font size="1" color="#666666"><span style="font-family:georgia,serif">Handong Global University (HGU), South Korea</span><br>
</font></div>
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<div><font color="#666666"><font size="1"><span style="font-family:garamond,"times new roman",serif">Homepage: </span></font></font><span style="font-size:x-small; color:rgb(102,102,102)"><a href="https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbuly.kr%2F74W1jXo&data=05%7C02%7Cfieldtrip%40science.ru.nl%7Ccecd588a60bc414b306908de2cc72f90%7C084578d9400d4a5aa7c7e76ca47af400%7C1%7C0%7C638997431156411596%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=M233WnvFbNPsbUyCraoJwPF5GptVVu4REaDqT5ISaA0%3D&reserved=0" originalSrc="https://buly.kr/74W1jXo" originalsrc="https://buly.kr/74W1jXo" originalsrc="https://buly.kr/74W1jXo" target="_blank">https://buly.kr/74W1jXo</a> </span></div>
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