Disabling both backends breaks Icinga Web UI

[Donien]

Describe the bug

This module relies on either the icingadb or the monitoring module.

When neither module is enabled but the businessprocess module itself is enabled, Icinga Web's UI breaks.

Navigation is no longer possible (using simple click navigation, URL paths can be used if the user knows them).

If disabling both possible backends, the UI breaks immediately.

Here I can still fix it be reenabling either backend.

Once I navigate away from this URL path, I'm out of luck.

Here no more useful clickable surfaces are available.

Screenshot using Vimium browser extension to highlight every button I could click

The only solution I found (apart from knowing the URL to toggle either backend) is to use icingacli module enable icingadb (in my case).

Not everyone - especially in production - will be able to access the CLI as well!

EDIT:
I've just noticed that I can click modules on the landing page, bringing me back to the modules screen. From there I can enable either backend.
Regardless of that, I still would not expect the UI to break this way.

To Reproduce

1. Install and enable (optional IcingaDB-Web and) BusinessProcess
2. Disable all possible backends (icingadb and monitoring)
3. Observe the error

Expected behavior

I would expect Icinga Web to work properly and the Business Process module to fail in a non-breaking manner (e.g. red banner with text).

Environment

Ubuntu 22.04

Icinga Web 2 Version 2.12.4 Git commit 219b11789beb0484b7993fa9ea838edd211ca5b2 PHP Version 8.1.2-1ubuntu2.21 Git commit date 2025-03-26

Loaded Libraries icinga/icinga-php-thirdparty 0.12.1 icinga/icinga-php-library 0.14.2

Loaded Modules businessprocess 2.5.1 (via git checkout) director 1.11.5 icingadb 1.1.3 incubator 0.22.0