I cannot view, edit or clone custom rules. I can translate them, delete them or clone them. Default rules seem to behave fine. When I try to edit/view/clone custom rules, I see a 500 error. However, it seems to be inconsistent in-so-much-as about one time in ten editing/viewing works.
The host I use is Japanese, but the upshot of their error message is that "CGI or possible SSI is not behaving correctly."
Is it similar to this issue from a couple of years ago? https://drupal.org/node/1258284