Werk #18868: Do not migrate HTML email format on empty parameters
| Component | Notifications | ||
| Title | Do not migrate HTML email format on empty parameters | ||
| Date | Nov 20, 2025 | ||
| Level | Trivial Change | ||
| Class | Bug Fix | ||
| Compatibility | Compatible - no manual interaction needed | ||
| Checkmk versions & editions |
|
This werk only affects you if you are upgrading from version 2.3 to 2.4 and use notification rules with the method ‘HTML email’ and the option ‘Cancel previous notifications.
Werk #18859 in 2.4.0p16 introduced a new migration of old HTML email "From" parameters. This update action could fail, preventing the update to continue, if notification rules with option "Cancel previous notifications" were used.
In such cases an error like "TypeError: argument of type 'NoneType' is not iterable" occurred.
A possible workaround was to disable notifications in version 2.3 using the “Master switch” in the sidebar and changing all HTML email notification rules with option "Cancel previous notifications” to “Create notifications with the following parameters” before updating. After the update, you simply switch the rules back to “Suppress all previous” and re-enable notifications via the “Master switch.”