Error when using Knir for unicode

[yuki-cossy]

Hi there,

I get this error when knitting a file and processing a data frame that has column names in Japanese.

Error: Can't rename columns that don't exist. x Column <U+985E><U+30FB><U+54C1><U+76EE> doesn't exist.

It says columns don't exist but they are actually existing.
The original columns' names are written in Unicode(Japanese), so I think that's the cause of this error.
Does anybody know how to fix this?
Thank you in advance!