Plugin Error

Errors in plugins? Retry to Update or Configure.

NoMethodError
undefined method `keys' for nil:NilClass
(plugin/blog-category.rb):140:in `blog_category_entry'
(TDiary::Plugin#eval_src):53:in `block in eval_src'
/home/yoshimura-s/www/blog/tdiary/plugin.rb:99:in `eval'
/home/yoshimura-s/www/blog/tdiary/plugin.rb:99:in `block in eval_src'
/home/yoshimura-s/www/blog/tdiary/core_ext.rb:112:in `block in safe'
/home/yoshimura-s/www/blog/tdiary/core_ext.rb:114:in `call'
/home/yoshimura-s/www/blog/tdiary/core_ext.rb:114:in `safe'
/home/yoshimura-s/www/blog/tdiary/plugin.rb:98:in `eval_src'
/home/yoshimura-s/www/blog/tdiary/base.rb:66:in `do_eval_rhtml'
/home/yoshimura-s/www/blog/tdiary/base.rb:30:in `eval_rhtml'
/home/yoshimura-s/www/blog/tdiary/dispatcher/index_main.rb:43:in `run'
/home/yoshimura-s/www/blog/tdiary/dispatcher/index_main.rb:6:in `run'
/home/yoshimura-s/www/blog/tdiary/dispatcher.rb:26:in `dispatch_cgi'
index.rb:32:in `<main>'