No .aup opens, all blocks always recognised as orphans

Points:

• Audacity 2.4.2 from source
• Debian buster, kernel 4.19.0
• Same project files were opening and closing before with the same filename, directory, Audacity binary etc.
• .aup files seem ok (see attachment)
• .au files in _data seem ok and play in Audacity
• For every saved project, including the freshly created one attached here, Audacity always identifies all .au as orphan blocks
• The block name in the orphan log message seems to match the block name in the .aup file (see screenshot, ‘save log’ isn’t working for me). For example, compare the first line in the log with from the .aup file:

<waveblock start="6553600">
  <simpleblockfile filename="eff1fea5.au" len="262144" min="-0,616146" max="0,714021" rms="0,054703"/>
</waveblock>

I have a month of labelling work on these .aup files. The labels are still there, but neither audio nor labels work. The audio track opens empty, and the labels track garbled (all labels at position 0).

I don’t remember anything major changing in my system. I changed linux kernel, did normal system updates. Both Audacity binary and files were left untouched.

How one would go about finding out what’s happening here?
test.aup (11.4 KB)

Oh wow! I eyed that first log message and recalled that I had recently changed the language from German to English to find a plugin’s name.

i changed the interface language back to German and now the .aup files open

Thanks for posting the solution.