I like the non-default "Material Reloaded" theme for mail headers. I installed it using the View→Headers→Download New Themes utility. When I select the option from the View menu, everything seems OK. But each time KMail starts, the setting has been lost, and the "Example" theme is active. Reproducible: Always Steps to Reproduce: 1. Install the Material Reloaded theme by ritze04 2. Activate the theme 3. Restart KMail Actual Results: The "Example" header theme is used. Expected Results: The header theme should still be "Material Reloaded".
Fixed long time ago. Please update your version to 4.14.x or kf5