Project import failed

[mschenone]

Describe the bug
Here is the report:

Version: 0.27.5
Path: /project/bf/dialogue
Info:
TypeError: t.items[l] is undefined
    in M/<@/imports/ui/components/stories/StoryGroupTree.jsx:1:1088
    in ja@http://167.71.190.137:8888/17cb0a85c6a8e16ebfbbd379c4ba3e6d45c59bb6.js?meteor_js_resource=true:49:77804
    in ForwardRef
    in f
    in div
    in div
    in t
    in div
    in t
    in f
    in P
    in ForwardRef
    in ForwardRef
    in withRouter(Component)
    in Connect(withRouter(Component))
    in Suspense
    in d
    in div
    in Unknown
    in div
    in t
    in div
    in t
    in div
    in div
    in z
    in ForwardRef
    in ForwardRef
    in Connect(Component)
    in c
    in Unknown
    in RouterContext
    in Router
    in o
    in c
    in t
    in DocumentTitle
    in SideEffect(DocumentTitle)
    in $

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Import Botfront Project'
2. Click on 'Upload stories'

Desktop (please complete the following information):

• OS: Linux
• Browser firefox
• Version 84.0

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.

First of all it looks like the data have been erased from the db. The app is hosted on a single server in cloud.
After importing successfully the project dump, I get the error above.