I made a few tests with the xml.
It seems tha the problem is with the asset "r149".
I don't know what it's supposed to be, but it looks different from all the others.
All that it has is this line:
<asset id="r149" uid="46F73DFFFDA6EB70998432ADCECCDA0A"/>
All other assets have other data like "name", "start", etc. This one is different. It is, however "used" further down the document.
I tried an experiment.
I removed the following seven lines where that asset is referred to - starting at line 5924:
<clip name="A014_08010810_C202" start="73627100/2500s" duration="207400/2500s" format="r148" tcFormat="NDF" modDate="2023-05-05 21:04:18 +0100">
<adjust-colorConform enabled="1" autoOrManual="manual" conformType="conformNone" peakNitsOfPQSource="1000" peakNitsOfSDRToPQSource="203"/>
<video ref="r149" offset="73627100/2500s" start="73627100/2500s" duration="207400/2500s">
<adjust-colorConform enabled="1" autoOrManual="manual" conformType="conformNone" peakNitsOfPQSource="1000" peakNitsOfSDRToPQSource="203"/>
<audio ref="r149" lane="-1" offset="21204604800/720000s" start="21204604800/720000s" duration="59731200/720000s" role="dialogue.dialogue-1" srcCh="1, 2"/>
</video>
</clip>
Then I removed the line above (it was 2953):
<asset id="r149" uid="46F73DFFFDA6EB70998432ADCECCDA0A"/>
After that, the xml imported with only a warning...
No guarantees, and of course no idea why this happened in the first place.