The default theme of blender has no `icon_border_intensity` and therefore only loads the regular icons. When newly loaded theme has the `icon_border_intensity` set it needs to reload the icon textures so both icon maps would be loaded. Without reloading the icons a GPU texture is missing and would crash blender at first use. Starting Blender the second time it would load the correct icons and would work as expected. Pull Request: https://projects.blender.org/blender/blender/pulls/113016