If you mean Krastorio 2... he has a habit of coding things oddly, and would rather declare them not compatible instead of fixing the issue.
In any case, if we're talking fuel item for the regular boiler, it's most likely due to him adding a new fuel category, without editing my boiler... which he doesn't really have any obligation to do, but it could be fixed.
if we're talking about a liquid powered boiler, he needs to give his liquid a fuel value.
I don't really have any working knowledge of Krastorio 2 beyond reading through some code that was causing an issue, suggesting a fix, and the end result being my mod marked as not compatible.
