One thing you can try would be to resign the macros. If this isn't a bug in Kentico, that may fix the issue, depends on if you have changed the web.config or moved the files from one server to another. Just a suggestion, as I haven't seen the issue before, but usually when I encounter something like this, resigning the macros works, unless it is an actual bug. I would suggest backing up the site first, just in case. I haven't had any issues occur, but better to be safe than sorry.