Smartthings device UI inaccessible, can't delete problematic device or DH ("in use") either

I’m currently unable to view or interact with my devices on my mobile device or online in the IDE. On my device I’m getting: “Something’s Wrong We can’t load your screen right now” and in the IDE I get an error message: when I click on the My Devices link:

Oh No! Something Went Wrong!

Error 500: Internal Server Error
URI /device/list
Reference Id 978e174f-50c2-4281-941c-5c72215d3d1b
Date Tue Oct 30 05:27:07 UTC 2018

I think it might be a problematic DH I’m working on that has children but while I can delete the parent DH, I’m blocked from deleting the child one since "DeviceType still in use by devices ". But since I can’t list/view the devices I’m effectively locked out.

Any suggestions?

Contact smartthings support