Non straightforward error message when failing to download a strings file

[tinsukE]

Running locca sync (v 2.0.0) I get the following error when fetching de/strings for my project:
error: undefined method children' for nil:NilClass`

Further investigation led to OneSky returning this error message (in the web interface):
We've encountered a problem when generating the file. Our engineering team will look into the issue and get back to you soon!

A nicer error message would be helpful!