REST API Explorer is not working in Developer instance

[Andrew Pishchul]

Today I noticed a weird issue - REST API Explorer stopped working in my Developer instance.. and looks it's not only my instance, I asked some of my friends and they have this issue too: the problem is that REST API does not provide the option to select a table and there are multiple errors in a browser console.

Geneva:

Fuji:

Can you guys check your developer instances and see if something has changed?

[Andrew Pishchul]

Cleared browser cache and the instance cache, that didn't help. But I found that REST API explorer works when Chrome/Firefox in incognito/private mode.