🐛 [BUG] - Experiment form crashes if you add an experiment without translated content and a block without translated content

[drikusroor]

Description

AttributeError at /admin/experiment/experiment/add/

'NoneType' object has no attribute 'language'

Request Method:	POST
http://localhost:8000/admin/experiment/experiment/add/
4.2.18
AttributeError
'NoneType' object has no attribute 'language'
/server/experiment/models.py, line 459, in get_fallback_content
django.contrib.admin.options.add_view
/usr/local/bin/python
3.12.9
['/server', '/usr/local/lib/python312.zip', '/usr/local/lib/python3.12', '/usr/local/lib/python3.12/lib-dynload', '/usr/local/lib/python3.12/site-packages']
Wed, 12 Feb 2025 16:09:38 +0100

Reproduction URL

http://localhost:8000/admin/experiment/experiment/add/

Reproduction steps

1. Go to http://localhost:8000/admin/experiment/experiment/add/
2. Fill in the experiment slug
3. Add a block to the phase, with a slug, rules, and playlist
4. Save

Logs

Browsers

No response

OS

No response

Additional context

No response