In Tuning Properties:
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Open ModPlug Tracker
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-Unable to import file "degung1.tun": unrecognized file.
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OK
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That doesn't look like a format that OpenMPT would support.
It supports its own binary .tun format and Scala .scl files (http://www.huygens-fokker.org/scala/scl_format.html) - your file is neither of the two.