Solved
Cannot save and build
After creating a rule and pressing "Save and build for development" button today, the whole UI has been stuck in building process for hours. I tried to initiate a new building, then both of them appear "pending". Neither Reloading the page nor sign out and -in again solves the issue.
Have debugged in browser network, I see request that is probably linked to build status check, whose response for meta appears as below:
meta":{"build_status":"pending","build_required_detail":"Last build was not successful"}}],"meta":{"pagination":{"current_page":1,"next_page":null,"prev_page":null,"total_pages":1,"total_count":1}}}
Now it is really stuck here, no work can be done there, please help asap.