[Bug]: Cannot Change Background For Server

[AlexTsuke]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Hello today I came across the error where you cannot change the background image of your Nextcloud server

Going into admin
theme
Change logo BG

The error in question: conflict between new type (mixed) and old type (string)

These issues were also recorded here:
#45083
https://help.nextcloud.com/t/problem-on-changing-background-type/196288

I and the hosting service I use HAVE been able to replicate the issue successfully and have noticed this issue has recently occurred. I have made NO changes to anything server related and was told to inform of this issue here

Steps to reproduce

1 Going into admin
2 theme
3 Change logo BG

Expected behavior

Change the background image

Nextcloud Server version

30

Operating system

Other

PHP engine version

PHP 8.0

Web server

Apache (supported)

Database engine version

MySQL

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

No response

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

[joshtrichards]

Duplicate of #48436