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Werk #19990: Fixed crash from invalid custom icon configuration

Component User interface
Title Fixed crash from invalid custom icon configuration
Date Jun 23, 2026
Level Trivial Change
Class Bug Fix
Compatibility Compatible - no manual interaction needed
Checkmk versions & editions
3.0.0b1
Not yet released
Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT
2.5.0p8
Not yet released
Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

Previously, if the Custom icons and actions global setting contained an icon value that was not a text name - for example an unset value - the GUI crashed when that icon was rendered.

Such invalid icon values now degrade gracefully to a "missing" icon placeholder instead of crashing the page. An invalid emblem value is likewise ignored rather than causing a crash.

When you update Checkmk, these non-text icon values are additionally rewritten to the missing icon, so the stored configuration is clean. Configured icon names are never changed: even a name that does not resolve today is kept, so the icon displays correctly again as soon as its icon file is added. No action is required on your part.

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