Clicking on invalid tags crashes the app

[Patitotective]

If you click on the Bootstrap tag in the Bootstrap dark theme, the app crashes because it is not a valid theme.

[rob-ross]

It might be useful for me to mention this as I have recently (successfully) used every theme in themes.toml while I am learning to use Dear ImGui. I write this as of June 29th, 2026, using Dear ImGui v1.91.1, which was the current public release version at this time. My backend is sfml v3.0.2, but I don't think the back end should matter for this information.

There were 2 issues with the themes.toml file when I first dowloaded it, but both have now been fixed. The only truly crashing issue was with the Red Oni theme which had the property ColorButtonPosition using value "None." The only valid values for this property are "Left" or "Right." The value "None" did cause an assert to fail which terminated the running app. But this has been fixed in the recent commit. It now has the value "Right" and no longer causes the assert to fail.

I didn't experience any other crashing issues with any of the other themes, and Red Oni now no longer crashes either.

The only other issue I personally encountered was with the Vullmad Dark theme. It wasn't crashing. But the rgb values set for it were using the wrong scale (float 0-1 actual versus int 0-255 expected.) This just caused the GUI widgets to appear to be drawn mostly black, making the theme unusable. I submitted a pull request to fix this and it has been added to the main branch. So Vullmad Dark is now a useable theme.

I encountered no other issues, and as of now none of these themes cause a crash and they all seem useable.