we have fixed the issues with the error message you were receiving. It seems your server is using an extension, called ‘mod_security’, which makes very paranoid restrictions to your environment.
You could face additional issues, which are not connected with our theme. You could ask your administrator to disable the ‘mod_security’ extension or at least increase its SecRequestBodyNoFilesLimit value.
This issue is very specific and rare, that’s why it took longer to resolve. Thanks for the patience.