Trouble editing an old course

[billadd...@gmail.com]

Hi

I set up some content on coursebuilder about three years ago. The webpages are still working fine but the content needs updated. I've not used coursebuilder since so am a bit rusty. 

I can connect OK to the admin page at http://MY-COURSE.appspot.com/modules/admin but the list of courses is empty. I have the correct options on the left -  Create, Style, Publish etc but most of them are greyed out. The only ones I can click are Courses and Help. If I click Courses then the URL changes to https://MY-COURSE.appspot.com/modules/admin?action=courses  and the full list of thr courses flashes up for a second but then goes blank again. It says 26 courses but I can't view any of them. 

Like I say, the actual site with the content is still available and working fine for users, but I can't work out how to edit it. I've tried a couple of different browsers and I've signed in with two different Editor accounts but the same result. Any idea where to turn next for troubleshooting?

Thank you