I using [geany-on-rails filetype](https://github.com/dejw/geany-on-rails/blob/master/geany/filedefs/filetypes....) (without [styling], I also updated the filetype_extensions.conf) with Geany 1.36 on Debian Testing, but the highlighting does not work with **.html.erb** files.
Perhaps one configuration line is missing somewhere? (I say that because there is no problem with .html.php and .php files)
example.html.erb: **ko** 
example.rb: ok 