500 Internal Server Error

Accept-Charset encoding error (CGI::InvalidEncoding)

/usr/pkg/lib/ruby/3.0.0/cgi/core.rb:682:in `block (2 levels) in initialize_query'
/usr/pkg/lib/ruby/3.0.0/cgi/core.rb:677:in `each'
/usr/pkg/lib/ruby/3.0.0/cgi/core.rb:677:in `block in initialize_query'
/usr/pkg/lib/ruby/3.0.0/cgi/core.rb:676:in `each'
/usr/pkg/lib/ruby/3.0.0/cgi/core.rb:676:in `initialize_query'
/usr/pkg/lib/ruby/3.0.0/cgi/core.rb:860:in `initialize'
/home/rin/public_html/tdiary-v5.2.1/lib/tdiary/dispatcher.rb:35:in `new'
/home/rin/public_html/tdiary-v5.2.1/lib/tdiary/dispatcher.rb:35:in `send_headers'
/home/rin/public_html/diary/index.rb:34:in `<main>'