Hi Asger,
Well, that looks like the XML is truncated, but can you provide the .sky file by putting it and any auxiliary files, like the .skyd and libraries into a ZIP file and posting the ZIP to:
https://skyline.ms/files.url
We will have a look. This is a highly unexpected result for a crash in Skyline, because Skyline saves to a temporary file and only renames it to being the current file once the save is complete. So, in theory, it shouldn't be possible to end up with a truncated file like this because of a problem in saving or a crash. I would expect that to result in a truncated temporary file with the prefix ~SKY but not your .sky file being truncated.
But, if you can share the file we will have a look and see what the current state is.
Sorry for the problem and for the crashes, which we would love to fix if you can give us any help in reproducing them.
--Brendan