This is more of a heads-up post.
This last month, I’ve had a number of Internal Server Errors coming up on one of my websites. The latest last week using Sendy. These errors are all down to Dreamhost’s modsec settings. These modsec settings are applied when you add Dreamhost’s extra security to your domain. I’ve not had problems all year, but in the past month it’s become such a pain that I turned this setting off in my hosting account. I have of course notified Dreamhost, but am posting here in case anyone else is tearing out their hair wondering what is going on.
If you get an internal server error, first turn of Dreamhost’s extra security feature for your domain, refresh your site and do what you’re doing again. If it works, you’ve found the cause of your problem.