I've checked this many times and the gem is installed. I get this error:
An unexpected error occurred: uninitialized constant Roo::Spreadsheet::Error
ruby 3.2.2 (2023-03-30 revision e51014f9c0) [arm64-darwin23]
roo (2.10.1)
I've not found any reference to this in the current issues list. I've deleted it, I've reinstalled it, I've cleared the Gemfile and the Gemfile.lock.